INTRODUCTION TO PACKET RADIO - PART 1 - by Larry Kenney, WB9LOZ
Packet Radio is the latest major development to hit the world of Amateur
Radio. If you haven't already been caught by the "packet bug", you're
probably wondering what it's all about and why so many people are so
excited about it. Well, continue reading, because you're about to find
out.
Packet seems to offer something different from other facets of Amateur
Radio, yet it can be used for everything from a local QSO to a DX contact
2500 miles away, for electronic mail, message transmission, emergency
communications, or just plain tinkering in the world of digital communi-
cations. It presents a new challenge for those tired of the QRM on the
low bands, a new mode for those already on FM, and a better, faster means
of message handling for those on RTTY. Packet is for the rag chewer, the
traffic handler, the experimenter, and the casual operator.
A ham can get involved very easily with relatively small out-of-pocket
expenses. All you need is a 2-meter transceiver, a computer or terminal,
and a TNC. If you have a DOS compatible computer, just a packet modem and
special software are needed instead of a TNC. You probably already have
the 2-meter rig and a computer of some kind, so all you need to buy is the
TNC, which costs just over $100, or the modem and software, which sell
together for about $50.
The TNC is the Terminal Node Controller, the little black box that's wired
between the computer and the radio. It acts very much like a modem used
for connecting a computer to the phone lines. It converts the data from
the computer into AFSK tones for transmission and changes the tones that
are received by the radio into data for the computer. It's a simple matter
of wiring up a plug and a couple jacks to become fully operational.
Packet is communications between people either direct or indirect. You can
work keyboard to keyboard or use electronic mailboxes or bulletin board
systems to leave messages. Due to the error checking by the TNC, all of it
is error free, too. (That is, as error free as the person at the keyboard
types it.) As the data is received it's continuously checked for errors,
and it isn't accepted unless it's correct. You don't miss the information
if it has errors, however, because the information is resent again. I'll
go into how this is accomplished in a later part of this series.
The data that is to be transmitted is collected in the TNC and sent as
bursts, or packets, of information; hence the name. Each packet has the
callsign or address of who it's going to, who it's coming from and the
route between the two stations included, along with the data and error
checking. Since up to 256 characters can be included in each packet, more
than three lines of text can be sent in a matter of a couple seconds.
There is plenty of time between packets for several stations to be using
the same frequency at the same time.
If all of this sounds confusing, don't let it bother you, because that
little black box, the TNC, does everything for you automatically. Packet
might seem very confusing at first, but in a day or two you're in there
with the best of them. In this series I'll be telling you more about
packet--how you get on the air, how to use it to your best advantage, and
ways to improve your operation. We'll talk about that little black box,
the TNC, and tell you about all its inner-most secrets. We'll discuss
mailboxes, bulletin board systems, and the packet networks that allow you
to work stations hundreds of miles away using just a low powered rig on 2
meters, 220 or 450. The world of packet radio awaits you!
- - - -
INTRODUCTION TO PACKET RADIO - PART 2 - by Larry Kenney, WB9LOZ
In the first part of this series I told you, in general terms, what packet
radio was all about...what it is, its uses, the equipment used and,
generally, how its transmitted. Now we're going to tell you how to get on
the air, make a QSO, and become familiar with your packet station. Whether
you're new to packet, having just received a new TNC, have been involved
for just a short time, or are one of the "old timers", this series should
help all of you. Even if you don't yet own a TNC, you should keep this
article handy for future use. I'll bet you'll be joining us soon!
The equipment needed to get on the air is a transceiver, a computer or
terminal, and a TNC - the terminal node controller - the little black box
we talked about in part 1. I highly recommend that you start with a 2
meter transceiver. There is packet activity on 220, 440 and on HF, but
2 meters is where all the action is and it's the best place to start out
on packet. The TNC contains a modem that is equivalent to the modem used
to connect your computer to the phone lines, but the tones used for packet
are different than those used on the phone. The TNC also contains special
software that's specially designed for ham radio packet use. If you own
an IBM computer or a compatible clone that uses DOS, you can buy software
for the computer that replaces the software in the TNC, so only the modem
portion of the TNC needs to be purchased.
When you buy a TNC or packet modem and take it out of the box, you'll find
cables supplied for connecting it to the radio, but you'll have to attach
the appropriate mic and speaker jack connectors for the radio you're going
to use. You also have to furnish the cable that connects the TNC to your
computer or terminal. In most cases, the standard RS-232 port is used
between the TNC and computer, however this varies with the type of computer
and TNC used. The operating manuals supplied with the TNCs have a good
write up on the various computers and the cabling needed. I would advise
that you read the introduction and set up procedures for your particular
TNC very carefully. Most companies have supplied excellent manuals, and
you shouldn't have any trouble figuring out your particular set up from the
the information supplied in the manual.
Once you have everything wired and connected together, turn on the computer,
load a terminal program (anything used for a phone modem will work well for
packet), set the parameters for 7bits, no parity and one stop bit and then
get into receive mode. Now turn on the radio, make sure the volume is
turned up about a quarter turn (about the "10 or 11 o'clock" position) and
make sure the squelch is set. It should be at the point where the background
noise disappers, just as it would be set for a voice QSO. Next, turn on the
TNC. You should get a "greeting" or sign on message from the TNC showing
the manufacturer's name, software version, etc. If you see a bunch of
gibberish, such as &tf$d.#ssan>m, it means that the data rate of the TNC and
computer are not the same. This data rate is better known as the baud rate.
The baud rate of the TNC has to match the baud rate used by your computer
terminal program and is easily adjusted. Check your TNC manual for this
procedure, as it varies from TNC to TNC. If you don't see a "greeting" or
the gibberish, check your cables and connections. Make sure that you have
everything connected properly, that the right wires are on the right pins,
and so on.
Now we need to explain the three levels of communicating you can do from
the keyboard. First, you can communicate with your computer for setting up
the terminal program; second, you can communicate with the TNC; and third,
you can communicate with the radio. It's very important that you know
which level you're in when working packet. I can't help you much with the
computer level, since that varies with manufacturer, model and the terminal
program you're using, but once you get the terminal program ready to receive
data, you're ready to talk to the TNC.
First, do a "control C" (press the CNTL and the letter C simultaneously);
this puts the TNC in COMMAND mode, the level where you communicate directly
with the TNC from the keyboard. You should see "cmd:" on your screen.
Enter: MYCALL - - - -
with your callsign in place of the dashed lines, such as: MYCALL WB9LOZ
followed by a carriage return (CR). All commands are followed by a (CR).
This sets into the TNC memory the call that you're going to use on the air.
Now if you type MYCALL (CR), it should respond with your call. If it does,
you've proven that the computer to TNC linkup is working fine. If you do
not see anything on the screen when you type, blindly enter the following:
ECHO ON (CR). If you see two of everything that you type, such as
MMYYCCAALLLL, enter ECHO OFF (CR).
You're now ready to go on the air! Tune the receiver to any odd numbered
frequency between 144.91 and 145.09 or 145.71 and 145.79 MHz and set the
rig for simplex operation. You might have to tune around for the frequency
with activity in your area.
Enter the following TNC commands:
MONITOR ON (CR)
MRPT ON (CR)
then watch the screen. You should soon be seeing the packets that are
being sent over the air by other stations. You should see something
similar to this:
WB9LOZ > W6PW-3: The meeting will be held at 8:00 pm.
This shows a packet being sent by WB9LOZ to W6PW-3. Watch for callsigns
with an asterisk next to it in packets that look like this:
WB9LOZ > W6PW-3,W6PW-1*: The meeting will be held at 8:00 pm.
This indicates that you're receiving the packet from W6PW-1, not the
originating station, WB9LOZ. Callsigns with an asterisk indicate that
you're copying the packet from that station, as it's being repeated, or
digipeated, by a packet repeater. Jot down the call, including any
trailing number attached to it.
On packet you can have up to 16 different stations on the air at the same
time using the same callsign. That's where the numbers at the end of the
callsign come into play. The calls W6PW, W6PW-1, W6PW-2, W6PW-3, W6PW-4
and W6PW-5 are all individual stations operating under the same station
license. A callsign without a number is the same as -0. These numbers are
called sub-station IDs or SSIDs, and are used to differentiate between the
various stations. There should never be more than one station using the
same callsign and SSID on the air at the same time.
Now, before you try to make your first QSO with someone else, you should
check out your equipment to make sure it's set up properly. To do that,
you can CONNECT to yourself. Note one of the callsigns you jotted down a
minute ago. Make sure your radio is still tuned to the frequency where you
heard that call, then enter the following:
C - - - - V - - - - (CR)
where the first dashed lines are YOUR callsign and the second dashed lines
are the call of the station you jotted down, including the SSID. The C
means CONNECT and the V means VIA. C WB9LOZ V W6PW-1 means connect to
WB9LOZ via W6PW-1. You should soon see "*** CONNECTED TO (your call)" on
the screen. You have now entered the third level of communications, called
CONVERSE mode, and this is where you communicate from the keyboard to the
radio. Anything you type on the keyboard will be transmitted over the air
as a packet every time you hit a (CR). If you enter "Test" (CR) you should
see "Test" a second time on the screen, as it's transmitted, then
digipeated and sent back to you. In this case you'll only be talking to
yourself via another station, but it's a good way to check to make sure
your system is working properly. If that works, hit a CONTROL C. This
puts you back into COMMAND mode where you talk to the TNC again. Enter D
(CR). This will disconnect you from the other station, and you'll see
"DISCONNECTED" on the screen.
Now you're ready to talk to someone else! Watch for a familiar call on the
screen while monitoring or note calls you see frequently. Be sure to note
whether or not a digipeater is being used by watching for the *. When the
station you want to contact is finished with his QSO, enter:
C - - - - or
C - - - - V - - - - (depending on whether or not a digipeater is
needed) followed by (CR). Replace the dashed lines after the "C" with the
call of the station you want to contact and the dashed lines after the "V"
with the digipeater call, if needed.
You should get a "*** CONNECTED TO ..." on the screen, which means you're
in converse mode, and your first QSO with someone else is underway!
Anything you type now will be sent to the other station, and anything he
types will be sent to you. When you're finished, be sure to do a CONTROL C
to get back into command mode, then enter D to disconnect from the other
station.
You're on the way now to lots of packet fun and adventure! If you are
still having problems at this point, contact a friend that has some
experience on packet and ask for help. The initial set up of the computer,
TNC and radio is probably the biggest stumbling block in packet. Any
experienced packeteer will be happy to help you get through this process to
get you on the air.
- - - -
INTRODUCTION TO PACKET RADIO - PART 3 - by Larry Kenney, WB9LOZ
In Part 2 I talked about how to get on the air and make your first QSO.
Now let's take a look at some of the commands that are available in your
TNC to help improve your station operation.
TNC COMMANDS: The TNC, or Terminal Node Controller, that "little black box"
we've talked about in the past, has more than 100 different commands for
you to use. You're able to customize your packet operating with these
commands and turn on and off various features as you wish. Not all TNCs
are exactly alike, but all have pretty much the same functions. I'll be
using the commands used by the TNC2 and clones in my examples.
We covered a few of the commands previously: CONTROL C for entering command
mode, MYCALL, MONITOR, CONNECT, and DISCONNECT. Now let's discuss a few
that can change the way your station functions.
ECHO: This command tells the TNC whether or not it should send what you
type back to the monitor screen. If you don't see anything when you type,
set ECHO to ON. IIff yyoouu sseeee ddoouubbllee, like that, set ECHO to
OFF. This setting will depend on how your particular computer system
functions.
CONV (converse mode): Your TNC will automatically switch to this mode
when you connect with someone, but you can also do it by entering CONV (CR)
at the Cmd: prompt. When in converse mode, anything you type will be
transmitted via the path you set with UNPROTO. (See the next paragraph.)
Anyone in monitor mode will be able to read what you transmit. Packets in
converse mode are sent only once and are not acknowledged, so there is no
guarantee that they'll get through. This mode is used frequently for
sending CQ's.
UNPROTO: This command designates the path used when in converse mode. The
default is CQ, but you can enter a series of digipeaters if you wish, or a
specific group or club name. Some examples:
CQ v WB6SDS-2,W6SG-1,AJ7L SFARC v W6PW-1,W6PW-4
Remember, you have to change UNPROTO for use on different frequencies,
unless you leave it set simply to "CQ".
FRACK: This determines how long your TNC will wait for an acknowledgement
before resending a packet. It shouldn't be set too short, or you simply
clutter up the frequency, yet it shouldn't be too long, or you'll spend too
much time waiting. I use FRACK set to 7, and have found that to be an
overall good value.
DWAIT: Used to avoid collisions, DWAIT is the number of time units the
TNC will wait after last hearing data on the channel before it transmits.
I have DWAIT set to 16, and have found that to work well.
PACLEN: Determines the number of characters in your packets, ranging from
1 to 256. The more characters you send per packet, the longer it takes to
transmit the information and the greater your chances are of noise,
interference or another station wiping it out. I've found a PACLEN of 80,
which is the length of one line, to be a good value. When working a
station nearby, PACLEN can be increased. When working a distant station,
it should be decreased.
RETRY: Your TNC will retransmit a packet if it doesn't receive an
acknowledgement from the station you're working. RETRY indicates the
number of times the TNC will try to get the packet through before giving
up and disconnecting. This can be set from 0 to 15, but I've found 8 to 10
to work well. Less than that causes an unnecessary disconnect if the
channel happens to be busy, but more than that clutters up the channel.
Do NOT set RETRY to 0. That means infinite retries, and serves no useful
purpose. It simply clutters up the frequency needlessly.
The following TNC commands affect the monitoring mode and what you see on
the screen:
MONITOR: This must be ON for you to monitor anything. When ON, you see
packets from other stations on the frequency you're tuned to. What packets
you see is determined by other commands from the list below. If MONITOR is
OFF, you see only packets sent to you while you're connected to another
station.
Note: On some TNCs, such as the AEA PK-232, monitoring functions are
selected by a number after the MONITOR command, such as MONITOR 3 or M 3.
Refer to your TNC operating manual for details.
MALL: If MALL is ON, you receive packets from stations that are connected
to other stations, as well as packets sent in unproto (unconnected) mode.
This should be ON for "reading the mail". If MALL is OFF, you receive only
packets sent in unproto mode by other stations.
MCOM: If ON, you see connect <C>, disconnect <D>, acknowledge <UA> and
busy <DM> frames in addition to information packets. If OFF, only
information packets are seen.
MCON: If ON, you see packets from other stations while you're connected
to someone else. This can get very confusing, but is useful when your path
is bad and you want to see if your packets are being digipeated okay. If
OFF, the monitoring of other stations is stopped when you're connected to
another station.
MRPT: If ON, you see a display of all the stations used as digipeaters
along with the station originating the packet and the destination station.
If OFF, you see only the originating and destination stations. For
example, if you have MRPT ON, you might see a transmission such as this:
K9AT>WB6QVU,W6PW-5*: I'll be leaving for the meeting at about 7:30.
If MRPT was OFF, the same transmission would look like this:
K9AT>WB6QVU: I'll be leaving for the meeting at about 7:30.
In the first case, you can see that the W6PW-5 digipeater was being used.
The asterick indicates which station you were hearing the packet from. In
the second case you have no idea if digipeaters are being used or what
station you were receiving.
HEADERLN: If you have this turned ON, the header of each packet is
printed on a separate line from the text. If OFF, both the header and
packet text are printed on the same line.
MSTAMP: Monitored packets show the date and the time the packet was
received if MSTAMP is ON. If it's OFF, the date/time stamp is not shown.
NOTE: The date and time must be entered using the DAYTIME command before
the MSTAMP command will function.
I run my station with all of these commands, except MCON, turned ON so that
I can really see what's happening on the frequency I'm monitoring. Try
various combinations of these commands and then decide on the combination
you like best for your station.
MORE COMMANDS - These are the basic TNC commands. I'll discuss many of the
other commands available to you later on in this series.
- - - -
INTRODUCTION TO PACKET RADIO - PART 4 - by Larry Kenney, WB9LOZ
USING DIGIPEATERS AND NODES:
DIGIPEATERS:
Digipeater is the term we use to describe a packet radio digital repeater.
Unlike the FM voice repeaters, most digipeaters operate on simplex and do
not receive and transmit simultaneously. They receive the digital infor-
mation, temporarily store it and then turn around and retransmit it.
Your TNC will allow you to enter up to eight digipeaters in your connect
sequence, but using more than 3 usually means long waits, lots of repeated
packets, and frequent disconnects, due to noise and other signals encount-
ered on the frequency.
When entering the list of digipeaters in your connect sequence, you must
make sure that you enter them in the exact order that your signal will use
them. You must separate the calls by commas, without any spaces, and the
EXACT callsigns must be used, including the SSID, if any. That means you
need to know what digipeaters are out there before you begin randomly
trying to connect to someone. Turn MONITOR ON and watch for the paths that
other stations are using.
Here are some examples of proper connect sequences:
C W6PW-3 v W6PW-1
C N6ZYX v WA6FSP-1,WD6EOB-3
C W6ABY-4 v K6MYX,N2WLP-2,AB6XO
The "v" means via. In the first example the sequence shown means: Connect
to W6PW-3 via W6PW-1.
Something to remember when using digipeaters is the difference between
making a connection and sending information packets. If the path isn't all
that good, you might be able to get a connect request through, but will
have a difficult time with packets after that. The connect request is
short so it has much less of a chance of being destroyed by noise or
collisions than a packet containing information. Keeping information
packets short can help keep retries down when the path is less than ideal.
NODES:
Net/Rom, TheNet, G8BPQ packet switch and KA-Node are names that refer to a
device called a packet node, another means of connecting to other packet
stations. Later on in this series you'll find a complete review of node
operation, but for now we'll cover the basics so that you can begin using
the node network. The difference you should note here is that you connect
to a node rather than using it in a connect path as you do with a digi-
peater.
First, you need to determine what nodes are located close to you. You can
do this by monitoring and watching for an ID or by watching to see what
other stations in your area are using. You'll note that most nodes have an
alias ID in addition to its callsign. Once you determine the callsign or
alias of a local node, you connect to it the same way as you connect to any
other packet station. You may use either the callsign or the alias to make
the connection. For example, the node I operate has the alias ID of SF and
the callsign of WB9LOZ-2, so you could connect to it using C SF or
C WB9LOZ-2. Either one will work.
When you connect to a node, your TNC automatically switches to converse
mode, just like when you connect to any packet station. Anything you now
type is sent to the node as a packet, and the node acknowledges each packet
back to your TNC. For the remainder of your connection your TNC works only
with this one node.
To use the node network to connect to another local station, you simply
enter a connect request as though you were connecting direct from your TNC,
such as: C K9AT. You do this, however, while you ARE STILL CONNECTED TO
THE NODE. The node will then retransmit your connect request and you'll
receive one of two responses: "Connected to (callsign)" or "Failure with
(callsign)". Once you're connected you hold your QSO just as if you had
connected direct or via a digipeater. When you're finished, go to command
mode on your TNC (Control C) and enter "D" (CR) and you will be discon-
nected from the node and the station you were working.
(NOTE: If the node you're using is a G8BPQ packet switch, it might have
several frequency ports. You'll have to enter a port number between the C
and the callsign in your connect request to indicate the frequency you want
to use, such as: C 2 K9AT. Enter "PORTS" for a port list.)
When you're connected to a node enter: NODES (or N) <CR> and you'll receive
a list of other nodes that you can reach on the network from the node you're
using. You'll note that the node list will vary in length and in the calls
listed as you move from frequency to frequency, since all frequencies are
not linked together. The list gives both an alias ID and a callsign for
each node. The alias ID often gives you a hint as to where the node is
located, but not always. To find out for sure where a node is located
you'll need to get a copy of the descriptive node listings that are avail-
able on most packet bulletin board systems. These complete lists give the
alias, callsign, location, frequency and other information on each node in
the network.
To connect to a station in another area using the node network you first
must determine which node is closest to the station you want to work. For
demonstration purposes, let's say we want to connect to N6ZYX. He's told
you he uses the the W6ABC-3 node, so you check the node list and see that
GOLD:W6ABC-3 is listed. WHILE STILL CONNECTED TO YOUR LOCAL NODE you first
connect to the distant node by sending a normal connect request, in this
case C GOLD or C W6ABC-3. Your TNC will send this as a packet to your
local node and your local node will acknowledge it. The network will then
go to work for you and find the best path between your local node and the
one you're trying to reach. You might have to be a little patient here, as
it sometimes takes a few minutes for the connection to be completed. You'll
then see one of two responses: "Connected to W6ABC-3" OR "Failure with
W6ABC-3". If it can't connect for some reason, try again later. It could
be that W6ABC-3 is temporarily off the air or the path has decayed and is
no longer available. We're going to be positive here and say we received
the first option.
Once you're connected to W6ABC-3, enter "C N6XYZ". Again, your TNC will
send this as a packet to your local node and the local node will acknowl-
edge it and send it down the path to W6ABC-3. W6ABC-3 will then attempt
to connect to N6XYZ. Here again you'll get one of the two responses:
"Connected to N6XYZ" OR "Failure with N6XYZ". If you get connected,
you hold your QSO just as you normally would, but there's one BIG
difference -- your TNC is receiving acknowledgements from your local
node, and N6XYZ is receiving acknowledgements from W6ABC-3. The acknowl-
edgements do not have to travel the entire distance between the two end
stations. Each node in the path handles the acknowledgement with the next
node in line. Because of this, retries are greatly reduced, and your
packets get through much faster.
When you're finished with the QSO, you disconnect in the normal manner --
go to Command Mode on your TNC and enter "D" <CR>. The entire path will
then disconnect automatically for you.
Nodes offer a variety of other features besides allowing you to connect to
other stations, and we'll look at those in parts 10 and 11 of this series.
- - - -
INTRODUCTION TO PACKET RADIO - PART 5 - by Larry Kenney, WB9LOZ
USING A PACKET BULLETIN BOARD SYSTEM
There are now dozens of different packet bulletin board system programs
available - W0RLI's, WA7MBL's, REBBS, MSYS, FBB, CBBS, and also some
personal programs such as WD6CMU's and N0ARY's. The commands are much
the same with each program, but you might find a few differences from
what I describe here. When you do, use the H - HELP command to get
specific details on how the BBS you're using functions.
You connect to a bulletin board system (BBS) exactly the same way as you
connect any other station. Once connected, you'll receive a welcoming
message, information on that particular BBS and instructions. Read the
information and instructions carefully. The first time you connect you
should receive a request to enter your name, QTH, zip code and home BBS
for the system user file. On some systems, the software will not allow
you to use any of the commands except HELP until you have entered this
information.
Note that after you receive the welcoming message and the instructions,
the last line ends with a >. This is known as the prompt. This is
where you enter the command you want performed next. Each command is
followed by a carriage return <CR> which you send by hitting the "Enter"
or "Return" key.
To enter your name you type the letter N followed by a space and then your
first name, such as: N Larry. Your QTH is entered using NQ followed by a
space then your full city name and two letter state abbreviation, such as:
NQ San Francisco, CA. You enter your zip code with NZ followed by a space
and your five-digit zip. Your "home BBS" is the system that you plan to
use regularly and want all of your personal messages delivered to. Make
sure that it's a full service BBS, not a personal mailbox, since only full
service systems are included in the message forwarding network. You enter
your home BBS by typing NH followed by a space and then the call of the
BBS, such as NH W6PW. (Note: SSIDs are not used with BBS operation except
for when making the connection. Most BBS software ignores all SSIDs.) The
user information is stored at the local BBS and is also sent to a central
data bank known as the "White Pages Directory". The information can be
accessed by anyone. System operators (sysops) use it for determining your
home BBS when forwarding messages, and you can use it to find the name, QTH
and home BBS of your friends. How to use the "White Pages" will be
discussed in part 9 of this series.
When checking in to a BBS for the first time, you should become familiar
with the commands available to you. Each BBS or mailbox is a little
different from the next, so read the introduction carefully and follow the
directions. If you don't know what to do next, enter H for the HELP
instructions. Make note of the command letters, enter only one command at
a time, and make sure you enter them correctly. Computers are not very
forgiving and expect things to be entered in proper form. Take your time,
check out the features that the BBS offers and enjoy yourself. There's no
need to feel rushed or intimidated. If you get to a point where you don't
know what to do next, don't give up and disconnect, enter H again for
further HELP. That's what it's there for! I suggest that you make a
printed copy of the complete help instructions so that you have them avail-
able as a reference when using the BBS.
Now let's go through the basic procedures you should follow when checking
into a BBS. If there are personal messages addressed to your call, the BBS
will list them for you following the welcome message. Note the message
numbers. At the > prompt, the first thing you should always do is list the
new messages, by entering L. The BBS program updates the user file each
time you check in, logging the latest message number. The next time you
check in, only the new messages that have been received by the system are
included in your list. The first time you check in, you might want to
avoid using L by itself. Many systems have more than 1000 active messages
available, and since you haven't seen any of them, the L by itself will
list all of them for you. As an alternative, I suggest that you use the
LL (LIST LAST) command. You enter LL followed by a space and then the
number of messages you'd like to see, such as LL 30 to list the last 30
messages that were received by the BBS. When you receive the list, note
the numbers of the messages you're interested in reading.
Next, read the messages you're interested in. You do this by entering
R XXXX, where the Xs represent the message number, such as R 4521. Note
that there is a space between the command and the number. It's best to
have your buffer or printer turned on when reading messages, because
they're apt to come in faster than you're able to read them. You should
have a means of saving them for reading later after you've disconnected.
If there were messages addressed to you, you should erase or "kill" them
once you've read them. You can do this with the "KM" command, which means
"Kill Mine". This command will erase all messages that are addressed to
you that have been read. You can also kill each message individually by
entering K XXXX, where the X's are the message number.
Once you've read all the messages you're interested in, you have several
options. You can look back at old messages, send messages to other
stations, see what's available in the file directories - the BBS library,
download a file, upload a file, check the list of stations that have
recently checked in to the BBS or stations that have been heard on the
BBS frequency, check the status of the BBS to find out what other stations
are connected and who has mail waiting for them, or a variety of other
things. We look at the BBS commands in detail in part 6 and explain how
to do all of these things and more.
Oh, so that we don't leave you connected forever, when you're ready to
disconnect from the BBS, enter a B.
- - - -
INTRODUCTION TO PACKET RADIO - PART 6 - by Larry Kenney, WB9LOZ
In part 5 we discussed the basics of using a packet bulletin board system.
Now let's look at the commands you use on a BBS. As previously mentioned,
some of the commands might vary slightly from the information I'll be
presenting to you here. Use H (HELP) if you find that a command doesn't
work as described. Remember, all commands must be followed by a carriage
return <CR>.
The LIST Command: The first thing you should do when connecting to a BBS
is to use the LIST command. There are many variations available, but L,
by itself, is the one used most often:
L (List) - Lists all new messages that have been received by the BBS
since you last logged in, except for other users' personal
messages.
If you want to list specific messages, you may use one of the following
variations of the L command:
LM - (List Mine) - Lists all messages addressed to you.
L # - Lists messages back to and including number #. Example:
L 4050 will list all messages, except personal messages to
others, from the latest one back to #4050.
LL #- Lists the last # messages. Example: LL 30 will list the last
30 messages received at the BBS, excluding others' personal
messages.
L> callsign - Lists all messages TO callsign indicated. Example:
L> N6XYZ
L< callsign - Lists all messages FROM callsign indicated. Example:
L< N6XYZ
L@ designator - Lists all messages that have that "designator" in
the @ BBS column of the message header. Example: L@ ALLCAN
will list all messages with ALLCAN in the @ BBS column.
There are several other variatons depending on the type of BBS you're using.
Enter: H L for more information.
READ COMMAND: To read a message, you enter R followed by a space then the
message number. Example: To read message 5723, you'd enter: R 5723. You
also have the option of using the RH command, which will give you all of
the forwarding headers in detail, rather than just giving you the path.
The forwarding headers show the list of BBSs that handled the message to
get it from the originating BBS to the one you're using. Example: To
read message 5723 with the full headers, you'd enter RH 5723. There is
one additional version of the READ command, and that's RM. Entering RM
by itself will give you all of the messages addressed to you that have not
yet been read.
ERASING MESSAGES: Once you have read a personal message, please erase it.
The sysop will appreciate your help in clearing up "dead" messages. You use
the K - KILL command to do this. You can enter K #, such as K 5723, which
will erase that particular message, or you can enter KM, which will erase
all of the personal messages you have read. If you use the KM command, the
BBS will list the message numbers for you as they're killed.
THE "S" COMMAND(S): S (Send) and on some systems S (Status):
On W0RLI-type systems, the letter S by itself will give you a reading of the
BBS status, showing the callsigns of stations using the system, the time that
they connected, the ports and tasks they're using, etc. It also shows you
information on the mail waiting for users and on the messages waiting to be
forwarded to other bulletin board systems. S by itself on other systems will
either prompt you for further information on sending a message, or it will
give you an "illegal command" error message.
SENDING A MESSAGE: The "S" command is mainly used for sending a message, but
it should always be used with another letter specifying the type of message
you're sending. There are three types of messages found on packet bulletin
board systems: Personal, Bulletin, and Traffic.
"SP" is used for sending a personal message to one other station,
"SB" for sending a bulletin, and
"ST" for sending a message that's going to be handled by the
National Traffic System.
You're able to send a message to one particular person, to everyone on the
local BBS, to everyone at every BBS in Northern California, in Southern
California, in the entire state, or all across the entire country. It all
depends on your addressing.
At the BBS prompt you enter the appropriate command (SP, SB, or ST) followed
by a space and then a callsign for a personal message or a category for
bulletins. The category should indicate the nature of the message, such as
PACKET, INFO, SALE, WANTED, DEBATE, ARES, etc. Examples: SP WB9LOZ SB INFO
SB SALE. NTS (National Traffic System) messages require special addressing
and a prescibed format, so I'll discuss them separately.
If you wish to send a personal message to someone at another BBS, you have
to indicate where it should be delivered. You do this by giving the call of
the other BBS and the two letter abbreviation of the state it's located in
following the call of the addressee. For example, to send a message to N5PQ,
who uses the W5XYZ BBS in Texas, you would enter: SP N5PQ @ W5XYZ.TX
The BBS call and the state abbreviation are separated by a period. This is
the bare minimum required for delivery of messages going out of state. A
more complete system of addressing is available. It's called hierarchical
addressing, and its covered in detail in the next part of this series. A
more complete address is helpful in directing your messages to stations in
the U.S more quickly and is required for messages going to stations outside
of the U.S.
To send bulletin, a general message, to more than just the local BBS, you
need to use a forwarding designator that specifies the area where you want
the message distributed. In northern California:
ALLCAN indicates that you want the message sent to all Northern
California BBSs, which includes all of them from Santa Cruz,
Gilroy, and Fresno northward.
ALLCAS is used to send a message to all BBSs in the southern part
of the state.
ALLCA is used for sending a message to EVERY BBS in the state.
ALLUSW is used for distribution to all BBSs in CA, AZ, NV, OR, and WA.
ALLUS is the designator to use for sending a message to EVERY BBS IN
THE USA. Extreme care should be used when using the ALLUS
designator. Please make sure that the subject matter is of
interest to packet users everywhere, that there are no time
constraints and that the message is as brief as possible. The
@ ALLUS designator should NOT be used for local meeting notices,
hamfest or swap meet announcements or for "Sale" messages. The
National HF Packet Network, used for forwarding messages to
other parts of the country, is somewhat fragile, due to varying
band conditions and the slower 300 baud rate used on HF, so
unnecessary traffic can keep personal messages, NTS traffic
and other more important traffic from getting through.
Here are a few examples of how you would correctly address a bulletin-type
message for general distribution:
SB PACKET @ ALLCA SB SALE @ ALLCAN SB INFO @ ALLCAS
NTS messages are entered as ST ZIPCODE @ NTSXX, where the XX is the two-
letter state abbreviation. Examples: ST 03452 @ NTSNH ST 60626 @ NTSIL
If you have traffic for the National Traffic System, you must use a special
NTS format for the text of the message. Full details on NTS messages will
be presented in Part 12 of this series.
When you have the address line of your message complete, you enter a
carriage return (<CR>). You'll then receive a prompt asking for the
SUBJECT or TITLE of the message. Enter a brief description (30 characters
or less) describing what the message will be about, followed by a <CR>.
You should attempt to describe the contents of your bulletin. What's it
about? This is the information that will determine whether or not someone
will read it or pass it by. For SALE or WANTED messages, be specific about
the equipment and include brand and model.
Next, you'll be asked to enter the TEXT of the message. When entering the
text, you should insert carriage returns at the end of each line, as if you
were typing a letter. A normal line has a maximum of 80 characters, so when
you have 70 to 75 characters typed, enter a carriage return and continue on
the next line. This will prevent words from wrapping around to the next
line and the program inserting an unnecessary blank line in the text. Some
programs require the carriage return or anything after the first 80 characters
will not be able to be read. After you have completed the text, you end the
message with a CONTROL Z. (You send a CONTROL Z by holding down the CONTROL
key and hitting the Z key.) You must follow the CONTROL Z with a carriage
return. (Some systems will also allow you to use /ex to end a message.) When
you receive the BBS prompt, you know that the message has been accepted by the
BBS.
FILE DIRECTORY COMMANDS:
The files on a BBS offer you a variety of information on a wide range of
subjects. Each BBS has its own unique set of files as determined by the
sysop (the system operator). They're stored in directories according to
subject and are listed by file name.
To determine what directories and files are available you use the W (What)
command. Entering W, by itself, gives you a list of the directories
available on the BBS along with an associated letter or topic name and a
general description of the subject for each directory. To list the files
stored in a specific directory you enter W followed the directory letter
or topic name that you received with the directory list. Example: WA or
W ARRL depending on the software used at your BBS. Enter: H W to find out
which form is used on your system.
If you want to read a file you use the D (Download) command. You enter D
followed by the letter or topic name for the directory where it's stored
and then the exact file name. Here are some examples: DF FCCEXAM.LST or
D FCC FCCEXAM.LST DM TS440S.MOD or D MODS TS440S.MOD You can enter
H D to find out which form is used on your BBS.
To send a file to the BBS you use the U (Upload) command. The command must
be used with the letter or topic name for the directory you want to store
the file in, followed by the filename you're assigning to the file. The
filename can have up to 8 characters preceding the period and 3 characters
following the period. (Normal DOS format.) Some examples: UG FLEAMKT.INF
or U GENERAL FLEAMKT.INF would upload a file named FLEAMKT.INF into the G
or GENERAL directory. UP BBSTIPS.01 or U PACKET BBSTIPS.01 would upload
the file BBSTIPS.01 into the P or PACKET directory. The BBS program will not
allow you to upload a file with a filename that already exists, and some
directories are set by your local sysop for downloading only so don't permit
you to upload files to them.
OTHER COMMANDS:
You'll find a variety of other commands available on your BBS, but which
ones you find depends on the software being used. Here is an explanation
of some of the ones you might find.
H (Help) - Every BBS has help available for the user. When you don't
understand how to use a command the help documentation will give you the
details. For help on a specific command enter: H followed by a space
and then the letter of the command you'd like more information about.
Example: H L will give you details on how to use the LIST command and its
many variations. H, by itself, will give you more information and specific
instructions on how to use the help documentation on your BBS.
C (Copy) - This command is used to make a copy of an existing message and
send it to another station. You must specify whether it will be a personal
message or a bulletin by following the C with a P or a B. The message number
to copy and the addressee follow. Example: CP 2568 KC6ZKM would make a
personal copy of message 2568 and address it to KC6ZKM. Enter H C for
complete information.
E (Edit) - If you enter a message and then notice that you made an error
entering the addressee's callsign, home BBS or address or decide you want to
change the Subject of the message, you may use the EDIT command to make the
desired changes. You can only change the message type, TO, BBS, Location
and Subject. You cannot edit the message text. Enter H E for details.
I (Info) - This command can give you details on the location of the BBS,
the hardware, software and RF facilities of the system you're using, or on
some systems, a page of upcoming events, helpful hints, or other useful
information. On W0RLI type BBSs, there are several other variations of the
I command:
I callsign - gives you the name, QTH, zip code and home BBS of the
person with that callsign, if listed in the local "White
Pages" packet directory. (More information on the packet
"White Pages" will be presented in part 9 of this series.)
Example: I K9AT
IZ zipcode - gives you a list of all active packet stations in the
specified zip code that are stored in the local "White
Pages". An asterisk maybe used in place of the end
numbers to give you a wider area. Examples: IZ 94114
would give you stations listed in the 94114 zip code only.
IZ 941* would give you the stations in all zip codes that
begin with 941.
I@ BBS - lists all callsigns in the "White Pages" having the
specified BBS as their home BBS. Example: I@ W6PW
IH location - lists all callsigns in the "White Pages" having the
specified location. Example: IH CA
Enter: H I for more detailed information on using this command.
J - Displays a listing of stations that were heard by the BBS or that
connected to the BBS. Must be used with a port identifier, such as JA, JB,
etc. J, by itself, will list the ports for you. You'll find several
variations of the J command depending on the type of software being used.
Enter: H J for details.
M - On MSYS BBSs M, by itself, will give you the message of the day.
N - Used for entering your name, QTH, zip code and home BBS. This command
was covered in detail in part 5.
P (Path) - On MSYS BBSs, P followed by a callsign will give you the path
last used by that station to connect to the BBS. Example: P W6PW
B (Bye) - When you're finished using the BBS, you enter a B to disconnect.
Remember, you might not find all of these commands on the BBS you're using,
and you might find others available that aren't listed here. Check your
local BBS for a complete list of the commands available to you.
- - - -
INTRODUCTION TO PACKET - PART 7 - by Larry Kenney, WB9LOZ
W0RLI, N6VV, and VE3GYQ devised a scheme called HIERARCHICAL ADDRESSING
for message forwarding on packet. With hierarchical routing designators
traffic routing is greatly improved. No longer will a missing call in
a BBS forwarding file cause a message to remain unforwarded, sysops will
no longer have to burn the midnight oil trying to keep their forward files
up to date, and messages will move much more directly toward their
destination.
The format for hierarchical routing is:
addressee-call @ BBS-call.#local area.state-province.country.continent
Example: My hierarchical packet address is WB9LOZ @ W6PW.#NOCAL.CA.USA.NA
It might look complicated, but it's not. First, note that each section of
the format is separated by a period. State and province codes are the
recognized two-character codes established by the US and Canadian Post
Offices. These may be found in the Callbook, your phone directory, or any
zip code listing. Don't guess on the state and province code if you aren't
sure what it is, and make sure you use only the two-letter abbreviation.
You could send the message to the wrong state or province or keep it from
being forwarded altogether. Codes used for the countries and continents
are standards, now accepted throughout the world. You should be able to
find a list of them in the file section of your BBS. The code for the
local area is optional, since you probably have no idea what code is being
used in upper New York state or in Iowa City, IA, for example. If you do
know the local code, please use it, since it will help get the message
closer to where it's going much more directly. The code for Northern
California is #NOCAL, the code for Central California is #CENCA and the code
for Southern California is #SOCA. For messages going outside of the US or
Canada, the local area is again optional and the state-province is not used.
Using the hierarchical format, here are some examples:
KB6LQV @ N6ZGY.#NOCAL.CA.USA.NA
KC6NVL @ K6VE.#SOCA.CA.USA.NA
KC3XC @ N4QQ.MD.USA.NA
VE3XYZ @ VE3RPT.ON.CAN.NA
JA1ABC @ JA1KSO.#42.JPN.AS
VK4AHD @ AX4BBS.AUS.OC
You'll note that the local area code is preceded by the octothorpe (now,
how's that for a $5 word?), better known as the number or pound sign. The
reason is that in Great Britain, Japan, and possibly other areas, they use
routing numbers for the local area, which could get confused with zip and
postal codes. Using the # on all local area codes will eliminate forwarding
problems.
We need to emphasize two very important points: hierarchical addressing
DOES NOT indicate a forwarding PATH, and ONLY ONE BBS call should be
included in the address. A list of BBS calls separated by periods will not
get your message to its destination. In fact, it can cause your message to
loop between BBSs and your message probably won't be delivered. The
addressing scheme is said to be one area inside another area. Using my
hierarchical address as an example, WB9LOZ @ W6PW.#NOCAL.CA.USA.NA, here's
how you would describe the address: "WB9LOZ at W6PW which is in Northern
California which is in California which is in the USA which is in North
America".
USING THE HIERARCHICAL ADDRESS: This section explains how the BBS soft-
ware uses the hierarchical addressing scheme. For an example, let's say
that we send a message to my friend Richard, KA7FYC, who uses the KD7HD
BBS in Missoula, MT as his home BBS. We would enter:
SP KA7FYC @ KD7HD.#MSL.MT.USA.NA
If the only entries in the forward file are California BBSs plus a list of
state abbreviations, country and continent codes, let's see how this message
would be forwarded. The the BBS software will attempt to find a match
between the items in the BBS forward file and the various parts of the
hierarchical address starting with the left-most item in the address field.
In our case, it would not find a match for KD7HD. If there isn't a match,
it then moves to the next section to the right. It wouldn't find a match
for #MSL, so it would again move to the right. Since all of the state
abbreviations are listed in the forward file, it would find MT and that match
would allow the message to be forwarded. The forward file would indicate the
call of the next BBS in line to receive a message addressed to MT. Once the
message is received at the next BBS, the process would start all over again
until the message is finally delivered to its destination.
Here are some comments from the ones who devised the hierarchical
addressing:
"There is another added benefit to this scheme. It involves Gatewaying
between the BBS world and other networks, such as TCP/IP via SMTP. Much of
the pioneer work in setting up the gatewaying protocols has been done by
NN2Z, N3EUA, and PA0GRI, amongst others. The W0RLI BBS package allows for
the forwarding of mail between the BBS world and the SMTP world. Of note
is the fact that the WA7MBL package has allowed such message exporting and
importing for some time now. This means that we can take advantage of the
the TCP/IP host-names and their domain or hierarchal format for forwarding.
Thus it is possible to send mail from the BBS to VE3BTZ as
ve3btz@pc.ve3btz.ampr.org or from SMTP to w0rli@w0rli.or.usa.na and not
have any ambiguity.
"The authors hope that this paper will serve as a starting place for
improved message routing by means of implicit routing. Low-level (VHF)
BBSs need only maintain state or province or country codes for distant
BBSs, and route such traffic to their nearest HF Gateway. In turn, the HF
station routes it to the desired state, where the receiving Gateway station
would have a detailed list of the BBSs it serves."
Comments from W0RLI, N6VV and VE3GYQ.
- - - -
INTRODUCTION TO PACKET RADIO - PART 8 - by Larry Kenney, WB9LOZ
This part of the series discusses the various parts of the packet message.
The following is an example of what you see when listing messages on a BBS.
On some systems the information is displayed in a different order, but the
same information is given.
MSG# STAT SIZE TO FROM @ BBS DATE/TIME SUBJECT
4723 P 1084 WD5TLQ WA6XYZ N5SLE 0604/1240 Software working great!
4721 BI 771 PACKET WB9LOZ ALLUSW 0604/1154 INTRO TO PACKET-Part 7 of 20
4717 BF 2387 EXAMS W6NLG ALLCAN 0604/1020 FCC Exams: March - June
4715 T 275 94114 W1AAR 0604/0959 QTC San Francisco 415-821
4712 BF 918 ALL N6ZYX ALLCAN 0604/0845 9600 BAUD DEMONSTRATION
The MESSAGE NUMBER is assigned by the BBS program when the message is
received and it cannot be changed. The numbers are assigned sequentially.
The STATUS of the message includes several different bits of information.
The first letter of the STATUS indicates the TYPE of message: B for
Bulletin, P for Personal, or T for Traffic for the National Traffic System.
Bulletins are messages of general interest to all users, and they can be
read by everyone using the system. Personal messages are listed only for
the sender, the addressee and the sysop, and they're the only ones who can
read them. The list above would have to have been requested by WD5TLQ,
WA6XYZ or a sysop. Can you see why? It lists an outgoing personal message.
(NOTE: Although personal messages can't be read by everyone using the BBS,
anyone in monitor mode can see a personal message as it's being sent over
the air, of course.) Traffic messages, type T, are listed for everyone and
can be read by anyone. In fact, all users are encouraged to participate in
the delivery of NTS messages addressed to your area. (Refer to part 12 of
this series for information on NTS messages.)
STATUS also shows if the message has been read, has already been forwarded
to all designated stations, is in the process of being forwarded, or is an
"old" message. You might see one of these letters: Y - yes, it has been
read, F - it has been forwarded, I - it's in the process of being forwarded
right now on another port, or O - the message has been on the BBS long
enough to become an "old" message. "Old" can be anywhere from 2 days for
an NTS message or up to 3 weeks for bulletins. The time frame for each
message type is specified by the local sysop. The "O" is mainly used to
catch the attention of the sysop. On some systems you'll also see N -
message not read or not forwarded.
The SIZE indicates the combined total of characters, including punctuation,
in the message text. The forwarding headers (explained below) are considered
to be part of the text and are included in the size. What starts out as a
short message can grow in size as it's forwarded from BBS to BBS.
TO is the callsign of the addressee for personal messages, the category or
interest group for bulletins and the zip code of the addressee for NTS
messages. While you might find bulletins addressed TO AMSAT, TO PACKET or
TO SALE, they're actually messages about AMSAT, about PACKET or about
equipment for SALE. You're apt to see anything in the TO column: ALL, USERS,
EXAMS, CODE, SALE, WANTED, DEBATE, SAT, PACKET, etc.
FROM shows the callsign of the station originating the message.
@ BBS is used for forwarding a personal message to someone at another BBS,
for forwarding NTS messages and for general distribution of a bulletin using
a forwarding designator. In the list shown above, the personal message would
automatically be forwarded to WD5TLQ at the N5SLE BBS. By entering a special
designator, such as ALLCAN, in the "@ BBS" column a bulletin may be forwarded
to specific areas. (See Parts 6 and 7 of this series for details on the
addressing of personal messages and bulletins and on using the forwarding
designators. Addressing of NTS messages is discussed in Part 12.)
Next is the DATE and TIME showing when the message was received at the BBS
you're using. If the message originated at another BBS, the date and time
when the message was originally entered will be shown in the forwarding
headers, as explained below, and at the top of the message when you read
it. The date and time indicated can be either local time or GMT (Zulu
time) depending on the time used by the BBS.
The SUBJECT (or TITLE) is a short description of the message content. For
bulletins, this is the information that determines whether or not someone is
going to read your message when he sees it in the message list. It should be
brief, but it also should be informative. You need to tell the other users
what the message is about as clearly and consisely as you can with just 30
characters.
The parts of the message mentioned so far are all seen when you ask for a
message list using the L (LIST) command. On some systems, entering a
semicolon after the list command (Example: LL 35 ;) will give you more
information about the message, such as the message ID, the full hierarchical
address, the number of times the message has been read, etc.
If a message has been forwarded from another BBS, forwarding headers are
added at the top of the actual message TEXT. This information is added by
each BBS that is used to get the message from its origination point to the
destination. Each BBS adds one line showing the time the message was
received by that particular BBS, its callsign and address, and possibly the
QTH, zip code, message number and other information. If you use the RH
command, rather than just R, when reading a message, such as RH 7823, you'll
receive complete headers. With just the R, headers are reduced to a list of
the BBS callsigns. The complete headers are useful if you want details on
the path a message took to reach you or how long it took to be forwarded from
system to system from the source to destination.
The TEXT of the message contains the information you want to convey to the
reader. It can be of any length. However, if the message will be going to
a distant BBS and will mostlikely be forwarded on the HF network, there is
a 2K size limit. This limit has been set by the HF gateway system operators
to keep traffic moving smoothly despite poor conditions and QRM. Extremely
long messages can tie up the forwarding system unnecessarily, so users are
advised to break up long messages into parts.
When entering a message into a BBS, use carriage returns at the ends of your
lines, as if you were using a typewriter. The normal screen width is 80
characters, so you should enter a carriage return prior to the 80th character
on each line. You shouldn't allow the automatic wrapping of lines to occur.
A message entered without carriage returns is very difficult to read, at best,
as words are cut at improper points, lines vary drastically in length, and
blank lines are often inserted. On some terminal programs and printers, any
line exceeding 80 characters without a carriage return inserted will not be
seen or printed past the 80th character. Your text might not be read in full
if you don't insert the carriage returns at the end of each line.
You should include your name, call and packet address at the end of the
text so that the person reading your message will be able to send a return
message to you if he or she wishes to do so. You end your message with a
control-Z or, on some systems, you may use /ex. This will tell the BBS to
save the message. Don't disconnect until you receive the prompt back from
the BBS, or your message may not be saved.
- - - - -
INTRODUCTION TO PACKET RADIO - Part 9 - by Larry Kenney, WB9LOZ
In this part of the series we're going to look at the White Pages. No,
not your local telephone directory, but the packet radio directory known
as the "White Pages". You help supply the information for "WP", and you
can also use it to find the home BBS, QTH and zip code of your friends on
packet.
"White Pages" was initially designed by Eric Williams, WD6CMU, of Richmond,
California. Hank Oredson, W0RLI, later added a WP database to his packet
bulletin board software, and now most of the BBS software programs have
some form of the White Pages available. It's a database of packet users
showing their name, home BBS, QTH and zip code. It's updated and queried by
packet message, allowing stations from all over the world to take advantage
of it.
When users enter their name and other information into their BBS user file,
it gets included in the WP database. The software automatically assembles
an update once a day containing all of the changes to the user information
it has received in the past 24 hours. This update is then forwarded to the
regional White Pages server. The regional server then takes all of the
information it has received and sends out updates to all other BBSs in the
area, as well as to AD8I in Ohio, the national White Pages Server. As a
result, you can easily find the name, home BBS, QTH and zip code of other
stations on packet all across the country using the White Pages database.
If your BBS is operating with its own WP database, you may make inquiries
of it using either the "I" or "Q" command, depending on the software being
used. Simply enter I or Q followed by the callsign you'd like information
about. If you wanted information on WB9LOZ, for example, you would enter:
I WB9LOZ or Q WB9LOZ
Check the help information on your BBS to see which command is the one used
there.
Information from the White Pages can be obtained by sending a query message
to your regional WP server or the national WP server, AD8I.#CMH.OH.USA.NA.
Since the messages are read and answered by the WP software, not a person,
you must use the correct format: <callsign> ? You may include as many
requests as you wish in each message, but each must be on a separate line.
Here's an example of a message sent to the AD8I White Pages database:
W6BBS> SP WP @ AD8I.#CMH.OH.USA.NA (The same format would be used
Enter subject of message: Query (to send a query message to your
Enter text: (regional WP database.)
K9AT ?
WA6DDM ?
K3AKK ?
W1KPL ?
(Control Z)
Capital and lower case letters may both be used within the message.
Just like all other packet messages, messages addressed to WP are forwarded
from BBS to BBS toward their destination. If a BBS operating with the
W0RLI WP Server handles a query message, it will respond with any pertinent
information that it has available. As a result, you might receive more
than one response to your WP query.
The WP program also collects data from any WP responses it sees, as well as
from the headers of every message that passes through. The information on
each call in a WP database is usually deleted in 90 days if it's not
updated. The time frame is determined by each local sysop.
It is important to note here that you should choose ONLY ONE BBS as your
home BBS, the one where you want all of your messages delivered. You should
also make sure that it is a full service BBS, not a personal mailbox, or
mail will not be forwarded to you. Always enter that callsign when you are
asked to enter your home BBS, even if you are using another system at the
time. It's also a good idea to include your home BBS, along with its full
hierarchical address, as the last line of the text in any message you send.
When a message arrives at the destination BBS given in the "@ BBS" column,
some of the BBS software will check the White Pages information to make sure
that the message has been delivered to the right place. If it finds that a
different BBS is listed as the addressee's home BBS, it will insert that BBS
callsign in the message and send it on its way. If you enter different home
BBS calls on several BBSs, your mail could easily end up being sent from BBS
to BBS and never reach you.
If you move or change your home BBS, you should then make sure that you
update the information for your call in the White Pages database. Use the
NH, NQ and NZ commands to update the information. Making sure that the
information in the White Pages is correct will help to get your messages
delivered to the correct BBS.
- - - -
INTRODUCTION TO PACKET RADIO - PART 10 - By Larry Kenney, WB9LOZ
In this and the next part of the series we're going to take an in depth
look at the packet node network. In part 4 I explained how to use the
network for connecting to another station. Now we'll look at the other
features a node offers.
Using the packet node network can make your operating time on packet more
enjoyable and it can greatly expand the area that you can reach. The
network of NET/ROM, TheNet, G8BPQ and KAM nodes is expanding very quickly
and now covers most of the country. New nodes are showing up almost daily.
Thanks to all of these stations and the interconnecting links, you can now
connect to stations in many far distant places using a low powered 2 meter
rig. Some nodes are set up for cross-banding, and with the introduction of
nodes on 10 meter FM, there's the possibility of working a station just
about anywhere.
A packet node, in most cases, is still set up for digipeater operation, so
you can still use it as a regular digipeater, but for most of your
connections you'll want to use the node features. Why? When using a string
of digipeaters your packets have to reach their destination parity correct
and the receiving TNC has to return an acknowledgement (ack) to your TNC for
each packet cycle to be completed. As you add more digipeaters to the string,
the chances of this happening become less and less. Other stations on the
frequencies used and noise along the route can be the cause of many retries.
When using a node, however, your packets no longer have to reach their
destination before acknowledgements are returned to your TNC. Each node
acknowledges your packet as its sent along the way toward its destination.
If you've been monitoring lately, you might have seen the nodes in action.
You might have wondered why they were sending all of those weird symbols
like @fx/<~|. What you're seeing is the nodes communicating with each
other and updating their node lists. You also might have noted callsigns
with high numbered SSIDs, such as WB9LOZ-14, WA6DDM-15, W6PW-12, etc. The
nodes change the SSID of all stations so that the packets sent via the
network are not the same as those sent directly. If you were to use a node
to connect to another station in the local area, there's the possibility of
your packets being received by this station both from you directly and from
the node. If the call through the node wasn't changed, the TNCs involved
would be totally confused as it would appear that two stations were
connecting using the same callsign. The node automatically changes the
SSID using the formula 15-N, where N is your usual SSID. A call with -0
becomes -15, a -1 becomes -14, -2 becomes -13, etc.
The node network is very simple to use. As explained in part 4, to use the
node network you first connect to a local node. It should be one where you
can connect to it direct with good signal strength. Once you've connected,
you then have several options -- connect to another station within range of
the node, connect to another node, connect to an associated BBS, obtain a
list of the nodes that are available, or check route and user status. On
NET/ROM and TheNet nodes you can also answer or call CQ.
There are several commands available on your local node. All have CONNECT,
NODES, ROUTES and USERS, and depending on the type of node you're using,
you might also find the BBS, BYE, CQ, INFO, MHEARD, PARMS or PORTS commands
available.
THE PACKET NODE COMMANDS:
CONNECT: The CONNECT command (which can be abbreviated as C) is used just
like you use the CONNECT command with your TNC. To connect to another
local station using a node, first connect to the node and then enter C
followed by the callsign of the station you want to reach. To connect to
another node you can use either the callsign or the alias. For example,
to connect to the SF:WB9LOZ-2 node you can use C WB9LOZ-2 or you can use
the alias, C SF . Either one will work.
There's a special consideration when making connections from a node using
the G8BPQ Packet Switch software. Since these nodes are capable of having
several different frequencies operating from the one node, you have to
indicate which frequency port you want to make your connection on. The
PORTS command, abbreviated P, will give you a list of the ports available,
such as this:
SF:WB9LOZ-2} Ports:
1 144.99 MHz
2 223.72 MHz
3 441.50 MHz
You then insert the port number between the C and the callsign, such as
C 1 WB6QVU, to indicate which frequency you want to use, in this case the
port 1 frequency of 144.99 MHz.
NODES COMMAND: The nodes command can be abbreviated as N and when entered
without any other information you'll receive a listing of other nodes that
can be worked from the node you're using. The list contains both the alias
and the callsign of each node. The alias might give you a hint of a node's
location, but you should have the California Packet Resources List available
to be able to tell where each node is located. (The CPRL lists are published
quarterly by Bob Alexander, AA6UP, and are available on most BBSs in the
state of California.) As you move from node to node, the list of nodes you
find will vary in length and will contain different callsigns, since all of
the frequencies are not linked.
The NODES command has a feature that gives you a simple way to find out how
easy it will be to connect to another node in the list. All you need to do
is enter N followed by either the alias or callsign of the node that you
want to reach, such as:
N FRESNO or N W6ZFN-2
You'll receive a report showing up to three routes to the node you asked
about, how good these routes are and how up to date the information is. If
there is no information available, you will receive either "Not found" or
the complete node list, depending on the type of node or switch you're
using.
Let's take a look at a typical report you would receive after entering
N FRESNO. If you were connected to a NET/ROM or TheNet node the report
would look like this:
SFW:W6PW-1} Routes to: FRESNO:W6ZFN-2
105 6 0 WB9LOZ-2
78 6 0 W6PW-6
61 5 0 WA8DRZ-7
If you were connected to a G8BPQ packet switch you would see one less
column in the report and it would look like this:
SF:WB9LOZ-2} Routes to: FRESNO:W6ZFN-2
> 126 6 W6PW-10
78 6 W6PW-6
60 4 W6PW-1
Each line is a route to the node you asked about. The symbol > indicates a
route that's in use. The first number is the quality of the route. 255 is
the best possible quality and means a direct connect via hard wire to a
coexisting node at the same site; zero is the worst, and means that the
route is locked out. 192 is about the best over the air quality you'll
find, and it usually means that the node is only one hop away. If you see
a quality of less than 80, you'll probably have a difficult time getting
any information through via that route. The second number is the
obsolescence count. This number is a 6 when the information for this route
is less than an hour old. For each hour that an update on the route is not
received, this number is decreased by one. A 5 means the information is an
hour old, a 4 means that it's two hours old, and so on. The next number,
shown only on NET/ROM and TheNet nodes, indicates the type of port. A 0 is
an HDLC port; a 1 is an RS-232 port. You don't need to pay any attention
to this figure. The callsign is that of the neighboring node that's next
in line on the route.
This quick check on a node that you want to reach can save you a lot of
time. You'll know immediately whether or not the node is available, and if
it is, how good the available routes are to it. You then won't have to
spend time trying to connect to a node that isn't available or is of poor
quality.
If you find that there's a decent route to the node or switch you want to
reach, it's normally best to let the network make the connection for you.
Simply enter a connect to the alias or callsign you want rather than
connecting to each individual node along the route yourself.
If a route exists but the quality is not very good, you might want to
connect to the neighboring node shown for the best route, then do another
quality check, repeating this procedure until you find a route with decent
quality. You can actually get through to some distant nodes using this
method if you have the time and patience to work on it.
(We continue with more commands used on the packet nodes in part 11)
- - -
INTRODUCTION TO PACKET - Part 11 - by Larry Kenney, WB9LOZ
COMMANDS USED ON THE PACKET NODE NETWORK - continued
ROUTES: The ROUTES command (abbreviated as R) will give you a list of the
direct routes to other nodes from the node you're using. The direct routes
are the ones where the node can connect directly to the other node. The
quality of each route is shown along with the obsolescence count. (See the
NODES command in part 10 for an explanantion of obsolescence count.) Any
route marked with an exclamation point (!) means that the route values have
been entered manually by the owner of the node and it usually means that the
route is not reliable for regular use.
USERS: The USERS command (abbreviated as U) will show you the callsigns of
all the stations using the node that you're connected to. There are five
descriptions used by the node to describe how users are connected:
UPLINK: The station indicated is connected directly to the node.
DOWNLINK: The node has made a connection from the first station to the
second station. Example: DOWNLINK (K9AT-15 N6UWK) would mean that
the node connected to N6UWK at the request of K9AT.
CIRCUIT: Indicates that the station indicated has connected FROM another
node if the callsign is on the left of the <--> and indicates that
the station has connected TO another node if it's on the right of the
<-->. If you see dashes between the arrows, the circuit is in use.
If you see <~~>, the connection is in progress. The alias and call
of any other nodes being used are shown prior to the user's call.
Examples:
Circuit (SFW:W6PW-1 WA6DDM) <--> AA6ZV
would mean that WA6DDM is using this node, that he connected to it
from the SFW node and is now connected to AA6ZV.
N6PGH <--> Circuit (DIA:WB6SDS-2 N6PGH)
would mean that N6PGH connected direct to this node and has connected
to the DIA node.
Circuit (SSF2:KA6EYH-2 KK6SD) <~~> (AMCYN:WZ6X-2)
indicates that KK6SD has connected to the node you're using from the
SSF2 node and is now attempting to connect to the AMCYN node.
CQ: See "CQ command" below.
HOST: The user is connected directly from the node terminal. This is
seen when the owner of the node is a user, or the BBS associated with
the node is using it to forward messages.
CQ COMMAND: The CQ command is used for calling CQ and for replying to the
CQ of another station. The CQ command is available only in the latest
version of NET/ROM and TheNet.
Using the CQ Command: The CQ command is used to transmit a short text
message from a node, and is also used to enable stations that receive the
transmission to connect to the station that originated it. The command is
entered as: CQ textmessage The "textmessage" is optional and can be any
information up to 77 characters long including spaces and punctuation. In
response to a CQ command, the node transmits the specified textmessage in
"unproto" mode, using the callsign of the originating user as the source
and "CQ" as the destination. As with all node transmissions, the SSID will
be translated; that is, the SSID will be 15-N, where N is the SSID of the
original callsign. WB9LOZ-0 would become WB9LOZ-15, WB9LOZ-1 would become
WB9LOZ-14, etc. Here is an example: If user station W6XYZ-3 connects to a
node and issues the command: "CQ Anybody around tonight?", the node would
then transmit: "W6XYZ-12>CQ:Anybody around tonight?" After making the
transmission in response to the CQ command, the node arms a mechanism to
permit other stations to reply to the CQ. A station wishing to reply may
do so simply by connecting to the originating callsign shown in the CQ
transmission (W6XYZ-12 in the example above). A CQ command remains armed
to accept replies for 15 minutes, or until the originating user issues
another command or disconnects from the node.
Any station connected to a node may determine if there are any other
stations awaiting a reply to a CQ by issuing a USERS command. An armed
CQ channel appears in the USERS display as:
(Circuit, Host, or Uplink) <~~> CQ(usercall).
The station may reply to such a pending CQ by issuing a CONNECT to the user
callsign specified in the CQ(...) portion of the USERS display--it is not
necessary for the station to disconnect from the node and reconnect.
Here's what a typical transmission would look like: (* = entered by user)
* cmd: C W6PW-1
cmd: *** Connected to W6PW-1
* USERS
{SFW:W6PW-1} NET/ROM 1.3 (669)
Uplink(K9AT)
Circuit(LAS:K7WS-1 W1XYZ) <~~> CQ(W1XYZ-15)
Uplink(WB6QVU) <--> Circuit(SFBBS:W6PW-3 WB6QVU)
* CONNECT W1XYZ-15
{SFW:W6PW-1} Connected to W1XYZ
* Hello! This is George in San Francisco
Hi George! Thanks for answering my CQ. etc.
Users of the CQ command are cautioned to be patient in waiting for a
response. Your CQ will remain armed for 15 minutes, and will be visible
to any user who issues a USERS command at the node during that time. Wait
at least five minutes before issuing another CQ to give other stations a
chance to reply to your first one! I've found that very few use the CQ
command, so don't be surprised if you don't see any CQ activity.
BBS: The BBS command (which cannot be abbreviated) is available on nodes
using the G8BPQ software where an associated packet bulletin board system
is operational. Entering BBS will connect you to the associated BBS.
BYE: The BYE command (abbreviated as B) is available on G8BPQ nodes and is
used to disconnect you from the node. It does the same thing as disconnecting.
IDENT: The IDENT command (abbreviated as I) found on NET/ROM nodes will give
you the identification of the node you're using.
INFO: The INFO command (abbreviated as I) found on TheNet nodes will give
you information about the node, usually the alias, callsign and location.
INFO: The INFO command (abbreviated as I) found on G8BPQ nodes will give
you the identification of the node and a list of the commands available.
MHEARD: The MHEARD command (abbreviated as M) found on G8BPQ nodes will give
you a list of stations heard by the node. If the node has more than one
port, you must specify which port you want the listing for by entering a
space after the M and then the port number. Examples: M 1 will give you a
list for port 1 and M 2 will give you a list for port 2. Use the PORTS (P)
command to get a list of the ports and the associated frequencies.
PARMS: The PARMS (Parameters) command (abbreviated as P) found on NET/ROM
nodes is for the owner's use in determining how his station is working.
PORTS: The PORTS command (abbreviated as P) found on G8GPQ nodes will list
the frequencies of all ports available.
- - -
INTRODUCTION TO PACKET RADIO - PART 12 - by Larry Kenney, WB9LOZ
The National Traffic System, known as NTS, is the ARRL sponsored Amateur
Radio message handling network. Packet radio is now playing a very
important part in the network, so let's take a look at the system and
give you some tips on handling NTS traffic by packet.
Handling third party traffic is the oldest tradition in amateur radio.
Nationwide, the National Traffic System has hundreds of local and section
nets meeting daily in order to facilitate the delivery and origination of
such messages. More and more of this traffic is being originated, relayed,
and delivered on packet. If you enjoy traffic handling, you can easily get
involved in NTS via packet. If you're on packet but know nothing about
NTS, this part of the series will get you off to a good start. At the end
you'll also find some references for further information on NTS.
Local packet BBSs have to be checked daily for traffic that needs to be
delivered or relayed. When you check into your local BBS, enter the LT
command, meaning "List Traffic". The BBS will display a list of all NTS
traffic awaiting delivery. It'll look similar to this example:
MSG# STAT SIZE TO FROM @BBS DATE/TIME SUBJECT
7893 T 486 60625 KB6ZYZ NTSIL 1227/0712 QTC1 CHICAGO, IL 312-267
7802 T 320 06234 WB6DOB NTSCT 1227/0655 QTC1 NEW HAVEN, CT
7854 T 588 93432 KA4YEA 1227/0625 QTC1 CRESTON, CA 93432
7839 T 412 94114 K3AKK 1227/0311 QTC1 SAN FRANCISCO 415-821
7781 T 298 94015 W1KPL 1226/2356 QTC1 DALY CITY, CA 415-992
You might see traffic that is being relayed by your local BBS to some other
part of the country as well as traffic for your local area. The "Subject"
or "Title" column of the listing will show the destination of the traffic.
If you see a message that is within your local area, help out and deliver
it.
RECEIVING A MESSAGE: To take a message off of the Bulletin Board for
telephone delivery, or for relay to a local NTS net, enter R followed by
the message number. Using the list above, R 7839 would send you the
message from K3AKK for San Francisco. You'll find the message in a special
NTS RADIOGRAM format, with a preamble, address, telephone number, text and
signature, ready for delivery. After the message has been saved to your
printer or disk, the message should be erased from the BBS. Use the K
command, as you do for killing your own messages. To kill message 7839,
for example, you'd enter: K 7839. This prevents the message from being
delivered again by someone else.
DELIVERING OR RELAYING A MESSAGE: Once you have received the NTS Radiogram,
it should, of course, be handled expeditiously. If it's for your immediate
area, you should deliver the message by telephone. If you took the message
for delivery to the local traffic net, you should make an effort to see
that it gets relayed as quickly as possible. If you're unable to deliver
the message, due to an incorrect phone number, no answer after several tries,
or some other problem, send a return message to the originator advising him
of the non-delivery, and why.
SENDING MESSAGES: Any amateur can originate a message on behalf of another
individual, whether the person is a licensed amateur or not. It is the
responsibility of the originating amateur, however, to see that the message
is in proper form before it's transmitted. A special format is used for
NTS traffic so that the messages are compatible across the entire network.
Each message should contain the following components in the order given:
number, precedence, handling instructions (optional), the station of
origin, check, place of origin, time filed, date, address, telephone
number, text and signature.
When the message is ready to be entered into your local BBS, you must use
the ST command, which means "Send Traffic", followed by the zip code of the
destination city, then @ NTS followed by the two letter state abbreviation.
The form used is ST ZIPCODE @ NTSxx. A message being sent to Boston, MA
02109 would be entered as follows: ST 02109 @ NTSMA and a message for Iowa
City, IA 52245 would be entered as ST 52245 @ NTSIA. The message SUBJECT
or TITLE should contain "QTC 1" followed by the destination city and state
and the telephone area code and exchange, if available. See the examples
in the listing above. Only one NTS message should be included in each
packet message. The actual radiogram should be included entirely within
the TEXT of the packet message, including all of the components listed
above. End the message with the usual Control-Z.
IN TIME OF EMERGENCY: The National Traffic System functions on a daily
basis as a public service for both your fellow hams and the general public.
It serves another function as well. The NTS provides a well oiled and
trained national system of experienced traffic handlers able to handle
large volumes of third party traffic accurately and efficiently during
disasters. Your participation now will help prepare you for that time
of emergency. Following the Loma Prieta Earthquake in October of 1989,
over 7000 NTS messages were handled by packet BBSs in the San Francisco
Bay Area. We needed and used all of the help we could get.
REFERENCE MATERIAL: The ARRL booklet "An Introduction to Operating an
Amateur Radio Station" offers detailed information on handling and
preparing NTS Radiograms. There are also many files with detailed
information on NTS available for downloading from your local BBS. They
give a complete rundown on how to prepare and send an NTS message on
packet, how to deliver NTS messages, etc. Check your local BBS files
section for them if you want to get involved. Your help will certainly
be welcome!
- - -
INTRODUCTION TO PACKET RADIO - Part 13 - by Larry Kenney, WB9LOZ
In this part of the series and the next we'll take a look at some of the
TNC commands available to you that we haven't covered previously. You
might find that some of the commands are not available in your particular
TNC or that they're used in a slightly different manner than what is
explained here. Not all TNCs operate exactly the same. Please refer to
your owner's manual for specific details on how to use these commands if
they don't function as described here.
8BITCONV: This command enables the transmission of 8-bit data in converse
mode. Used with AWLEN - see below. For normal packet operation, such as
keyboard to keyboard transmissions, use of bulletin board systems, and the
transmission of ASCII files, 8BITCONV should be OFF. If you need to
transmit 8-bit data, set 8BITCONV ON and set AWLEN to 8. Make sure that
the TNC at the receiving end is also set up this way. This procedure is
normally used for transmission of executable files or a special non-ASCII
data set.
AWLEN: This parameter defines the word length used by the serial
input/output port of your TNC. For normal packet operation, as described
above, AWLEN should be set to 7. Set to 8 only if you're going to send
8-bit data.
AX25L2V2: This command determines which level of AX.25 protocol you're
going to use. If OFF, the TNC will use AX.25 Level 2, Version 1.0. If ON,
the TNC will use AX.25 Level 2, Version 2.0. Note: Some early TNCs will
not digipeat Version 2.0 packets. With AX25L2V2 OFF, if your TNC sends a
packet and the packet doesn't get acknowledged the first time it was sent,
it will send it again and again, until an "ack" is received or the TNC
retries out. With AX25 ON, if your TNC sends a packet and doesn't receive
an "ack" the first time, it will send a poll frame to see if the other TNC
received the packet. If yes, then it would continue, if not then it would
send the last packet again. The advantage here is that short poll frames
are sent, rather than long packets containing data. This can greatly
reduce channel congestion. For VHF/UHF operation, it is almost essential
that every TNC have AX25L2V2 ON. Many operators have suggested that
Version 2.0 NOT be used on the HF bands as it tends to clutter the
frequency with poll frames. See the CHECK command below for related
information.
BEACON: Used with EVERY or AFTER to enable beacon transmissions.
BEACON EVERY n - send a beacon at regular intervals specified by n.
BEACON AFTER n - send a beacon once after a time interval specified
by n having no packet activity.
n = 0 to 250 - specifies beacon timing in ten second intervals.
1 = 10 seconds, 2 = 20 seconds, 30 = 300 seconds or
5 minutes, 180 = 1800 seconds or 30 minutes, etc.
For example, if you set BEACON EVERY 180 (B E 180), the TNC will transmit
a beacon every 30 minutes. If you set BEACON AFTER 180 (B A 180), the TNC
will transmit a beacon after it hears no activity on the frequency for 30
minutes. B E 0 will turn the beacon off. The text of the beacon is
specified by BTEXT and can contain up to 120 characters. The path used for
the beacon transmission is specified by the UNPROTO command. YOU SHOULD
USE BEACONS INTELLIGENTLY! Beacons are often a point of controversy in
the packet community because they tend to clutter the frequency if used
too frequently. You should keep your beacons short and infrequent, and
they should only be used for meaningful data. Bulletin boards use the
beacon for advising the community of who has mail waiting for them, clubs
use beacons for meeting announcements, and beacons are used for severe
weather warnings. They should not be used just to let everyone know that
you're monitoring the frequency, that your mailbox is ready, or that you'd
like someone to connect to you. You should monitor the frequency for
activity and make some connections yourself.
CHECK n Sets a timeout value for a packet connection. When a connection
between your station and another seems to "disappear" due to changing
propagation, channel congestion or loss of the path, your TNC could remain
in the connected state indefinitely. If the CHECK command is set to a value
other than 0, the TNC will attempt to recover the connection or disconnect.
The action taken depends on the setting of AX25L2V2. The value of CHECK (n)
may be set from 0 to 250 and the timing is based on the formula of n * 10
seconds. (n = 1 = 10 seconds, n = 5 = 50 seconds, n = 30 = 300 seconds or
5 minutes, etc. A value of 30 is a recommended value to use.) If CHECK
is set to 0, it disables the command. If AX25L2V2 is ON, the TNC will send
a "check packet" to verify the presence of the other station if no packets
have been heard after (n * 10) seconds. If a response to the "check packet"
is received, the connection will remain. If no response is received, the
TNC will begin the disconnect sequence, just as if the DISCONNECT command
had been sent. If AX25L2V2 is OFF, after no packets are heard for n * 10
seconds, the TNC will not send a check packet, but will begin the disconnect
sequence.
CMSG Enables the automatic sending of a connect message whenever a
station connects to your TNC. If CMSG is ON, the TNC will send the message
contained in CTEXT as the first packet of the connection. CTEXT can
contain up to 120 characters. Of course, you must have a message in CTEXT
for CMSG to function. This feature is often used when the station is on
but the operator is not present. The connect message is used to advise the
other station of that fact, and often says to leave a message in the TNC
buffer or mailbox. If CMSG is OFF, the CTEXT message is not transmitted.
KISS KISS enables the TNC to act as a modem for a host computer,
allowing programs such as TCP/IP, the G8BPQ Packet Switch, various BBS
programs, and other programs using the Serial Link Interface Protocal
(SLIP) to be run. Before turning KISS on, set the radio baud rate and
terminal baud rate to the desired values. Set KISS to ON and then issue a
RESTART command.
(continued in part 14)
- - - -
INTRODUCTION TO PACKET - Part 14 - by Larry Kenney, WB9LOZ
TNC COMMANDS - continued from Part 13
MAXFRAME Sets the upper limit on the number of unacknowledged packets
the TNC can have outstanding at any time. (The outstanding packets are
those that have been sent but have not been acknowledged.) MAXFRAME also
determines the maximum number of contiguous packets that can be sent during
one transmission. The value can be set from 1 to 7. The best value to use
depends on the frequency conditions. The better the conditions are, the
higher the value you can use. If conditions are poor due to frequency
congestion, noise, or other variables, (shown by lots of retries) MAXFRAME
should be reduced to improve throughput. The best value of MAXFRAME is
determined through experimentation. MAXFRAME of 1 should be used for best
results on HF packet.
MFILTER This command allows you to enter up to four ASCII character
codes, 0 - $7F, for the control characters that you want eliminated from
your monitored packets. Codes may be entered in either Hex or Decimal.
Here are the ASCII codes for some of the more troublesome control
characters found in monitored packets:
HEX DEC FUNCTION POSSIBLE RESULT
$07 07 Control G Rings your bell or "beeps" your speaker
$0C 12 Control L Form feed - could clear your screen
$13 19 Control S Can cause your screen to stop scrolling
$1A 26 Control Z Can clear your screen
$1B 27 Escape Can cause your cursor to move to a random
point on your screen and can raise havoc
with printer control.
AEA has added a new code, $80, that will not allow ANY control characters
to be displayed on the user's screen from monitored packets.
MHEARD An immediate command that causes the TNC to display a list of
stations that have been heard since the command MHCLEAR was given or the
TNC was powered on. This command is useful for determining what stations
can be worked from your QTH. Stations that are heard through digipeaters
are marked with an * on most TNCs. On the AEA PK-232, the stations heard
direct are marked with the *. (Check your TNC manual.) The maximum number
of stations in the list is 18. If more stations are heard, earlier entries
are discarded. Logging of stations heard is disabled when the PASSALL
command is ON. (See below.) If the DAYTIME command has been used to set
the date and time, entries in the MHEARD list will show the date and time
the stations were heard.
PASSALL Causes the TNC to display packets that have invalid checksums.
The error-checking is disabled. If PASSALL is ON, packets are accepted for
display, despite checksum errors, if they consist of an even multiple of
eight bits and are up to 330 bytes. The TNC attempts to decode the address
field and display the callsigns in standard format, followed by the text of
the packet. PASSALL can be useful for testing marginal paths or for
operation under unusual conditions. PASSALL is normally turned OFF.
PERSIST Used in conjunction with the SLOTTIME command (see below) to
provide less clutter on a busy packet frequency. As more and more TNCs
are upgraded to include the PERSIST and SLOTTIME commands, fewer and fewer
packet collisions will occur. If you have these commands availble in your
TNC, you should set DWAIT to 0 and set these commands for use. Note: On
some TNCs, such as the PK-232, you have another command that determines
whether you use DWAIT or PERSIST/SLOTTIME. It's the PPERSIST command
(with 2 P's). Set it ON to use PERSIST/SLOTTIME; set it OFF to use DWAIT.
I strongly recommend that you set PPERSIST to ON.
PERSIST specifies a threshhold value for a random-number attempt to transmit.
The value ranges from 0 to 255. 0 signifies a 1/256th chance of transmitting
every SLOTTIME; 255 allows the TNC to key the transmitter every SLOTTIME.
Through experimentation, it has been determined that the best value for
PERSIST is in the 60 to 70 range.
SLOTTIME This command determines the time interval the TNC waits between
generating random numbers to see if it can transmit. This random number
generation and the value of PERSIST work together to provide smoother
operation on a busy packet frequency. The SLOTTIME value may be set from
0 to 250. Through experimentation it has been determined that the best
value for SLOTTIME is in the range of 10 to 20.
SCREENLN n This parameter determines the length of a line of text on your
computer screen. The value may be 0 to 255, and is usually set to 40 or
80 depending on the screen display you have. A carriage return and line
feed (CR/LF) are sent to the terminal in Command and Converse modes when n
characters have been displayed. A value of zero inhibits this action.
If your computer automatically formats output lines, this feature should be
disabled.
TRANS This is an immediate command causing the TNC to change from
Command mode to Transparent Mode. Transparent mode is used when you want
to send data such as executable programs where characters in the data would
conflict with the operation of the TNC. Characters such as "Control C",
"Control R", "Control S", "carriage return", "linefeed", etc. all effect
the operation of the TNC when in Converse Mode. In Transparent Mode none
of the data characters affect the operation. All eight bits of each
character are sent to the radio exactly as they are received by the TNC from
the computer or keyboard. Packets are transmitted at regular intervals set
by the PACTIME command or whenever a full packet of information is ready.
The receiving TNC must also be in Transparent mode and nodes and digipeaters
cannot be used in the transmit path. Since the characters normally used for
TNC operation have no affect in this mode, a special procedure is required
to exit Transparent Mode and return to Command Mode. Refer to your TNC
operating manual for details on how this procedure is performed on your
particular TNC. You should also check your manual for information on the
CMDTIME, PACTIME, START, STOP, TRFLOW, TXFLOW, XFLOW, XOFF and XON commands
before using Transparent Mode.
TXDELAY n This parameter tells the TNC how long to wait before sending
data after it has keyed the transmitter. All transmitters need some start
up time to put a signal on the air. Some need more, some need less.
Synthesized radios and radios with mechanical relays need more time, while
crystal controlled radios and radios with diode switching require less
time. External amplifiers usually require additional delay. Experiment to
determine the best value for your particular radio. TXDELAY can also be
useful to compensate for slow AGC recovery or squelch release times at the
distant station.
There are many additional commands available to you. Spend some time
reading the owner's operating manual that came with your TNC to discover
some of the surprises the other commands offer. New versions of the TNC
software have added several commands that you might find useful in your
packet operating.
- - - -
INTRODUCTION TO PACKET RADIO - Part 15 - by Larry Kenney, WB9LOZ
Here are some tips to help make your packet operating more enjoyable.
Whether it's while making local QSOs, checking into a BBS or mailbox, or
working DX, there are a few things you should take into consideration that
will help eliminate problems and waiting time, increase your "throughput"
and make packet a lot more fun. ("Throughput" is a word that has come
into common useage by packet operators and means the amount of usable
packet information transmitted or received.)
When connecting to another station, don't use a digipeater or node unless
you have to. Each digipeater you add to the path increases the time
required to get your signal to its destination and to get an acknowledgement
returned. It also increases the chance for interference and for collisions
with other packets. You'll be amazed at the difference in throughput when
comparing a direct connect to one with just one digipeater in the path.
The packet node network, as discussed in previous articles in this series,
does a great deal to help you get your packets through, but you must
remember that throughput there, too, is affected by the number of nodes used
and by the conditions between you and the destination station. The big
advantage of the nodes is that the acknowledgements do not have to return
all the way from the destination station before your TNC is satisfied.
Packets are acknowledged from node to node, so that eliminates a large part
of the problems encountered. Getting the original packet through, however,
remains to be as much of a problem for the nodes as it is for you when using
digipeaters. It can take several minutes to get a packet through when you're
working a station some distance away. Have patience!
Dr. Tom Clark, W3IWI, has determined that for EACH HOP in a packet path the
loss of packets can vary anywhere from 5% to 50% depending on the amount of
traffic. Remember, each digipeater and node adds a hop, so multiply those
percentages by the number of hops, then multiply by 2 to account for the
acknowledgement, and you can see how quickly the path deteriorates as
traffic increases and digipeaters and nodes are added to it.
If you have a choice, use a frequency that doesn't have a lot of other
traffic on it. It makes sense that the more stations there are on a
frequency, the more chances there are for collisions and retries. A path
that will work perfectly without a lot of traffic, can become totally
useless under heavy traffic conditions. Just one additional station on
the frequency can decrease throughput by about half in many cases.
Another consideration, especially if working over a long distance, is
atmospheric conditions. You might not have experienced this before on VHF,
but with packet's high sensitivity to noise, a slight change in signal
strength can mean the difference between getting your packets through or
not getting them through. Long paths between nodes are very susceptible
to these changing conditions. There are times, especially on a hot summer
day, when it's impossible to get a packet from one node to the other on
what is normally a good path. In the San Francisco Bay Area, the fog has
a drastic affect on VHF signals. When a fog bank is moving in off the
Pacific, it can act as an excellent reflector. Signals that normally aren't
heard or are very weak can reach signal strengths of 40 over S9.
Multipath is another problem that can greatly affect your packet signal.
Multipath is the term used to describe the receipt of multiple signals from
one source due to reflections off of buildings, hills or mountains. The
"ghost" in a television picture is a form of multipath. A station with a
very strong signal into a digipeater or node often cannot use that path if
multipath causes the signal to be distorted. Each packet is checked for
100% accuracy and is not acknowledged unless it is. Multipath reflection
can cause occasional bits to be lost so you can end up with multiple retries
and a poor path even with strong signals.
To sum up, for best results on VHF use the least number of digipeaters and
nodes as possible, use a frequency with low activity, and be aware of
atmospheric conditions and multipath problems. Remember, by decreasing
PACLEN and MAXFRAME in your TNC, you improve your chances of getting packets
through under poor conditions.
If you use packet on HF, remember to change your transmit baud rate to 300
and to use a short PACLEN (a value of 40 seems to work quite well) and a
MAXFRAME of 1. The chances of getting a short packet through the noise and
QRM are much better than for a long one.
_ _ _
INTRODUCTION TO PACKET RADIO - Part 16 - by Larry Kenney, WB9LOZ
PUTTING TCP/IP ON THE AIR - Part 1
INTRODUCTION
Getting your station set up for TCP/IP operation will require some time
and effort on your part. You just can't put a disk in your computer and go
on the air. You have to get an IP address, set up specific directories,
get some needed files, and make up a few necessary files for your own
operation. You also need a TNC that operates in KISS mode. Most now have
the KISS command available, but check your TNC operating manual before you
start anything else to ensure that the KISS command is available in your
TNC. Also while you have the manual out, learn how to use the KISS
command; it works differently from most commands you're familiar with.
THE SOFTWARE
The first thing you need, of course, is the software. The KA9Q
Internet Package, commonly called NET, is the most common program in use
today. There are versions available for the PC and clones, the Macintosh,
Amiga and Unix. Where do you get it? The easiest source is a local ham
that has a copy of the version you need. Put a message on your local BBS
to see if there is anyone in your area that is already on TCP/IP. Not only
will you be able to get the software from him, but you'll have someone to
ask questions of if you have problems.
The Tucson Amateur Packet Radio Association (TAPR) has the version for
the PC and clones available for $4.00. This is a special "Plug and Play"
set of disks with sample files included along with instructions for setting
up your hard drive with the proper directories. You can write to them at
TAPR, PO Box 12925, Tucson, AZ 85732, or call them at (602) 749-9479.
If you have a telephone modem, there are several sources available to
you. You can download the package from some of the ham related telephone
BBSs. It's available from Dennis Humphrey, WA6RDH's BBS in California at
(916) 678-1535, from Howard Leadmon, WB3FFV's BBS in Maryland at
(301)-335-0858, or from Gary Sanders, N8EMR's BBS in Ohio at
(614)-457-4227. All accept 1200/2400, 8 bits, no parity, 1 stop bit. The
software is also available from Compuserve in the Hamnet section. If you
have a DRSI plug-in TNC, you already have what you need. A copy of the
TCP/IP software that has already been configured for use with the DRSI card
was included with it.
IP ADDRESS
In addition to the software, you also need to obtain an IP address.
This is a series of numbers that will uniquely identify your station on the
air. To get an address assigned you need to contact the IP address
coordinator in your area. Ask around to find out who the local coordinator
is, or contact Brian Kantor, WB6CYT, the national IP address coordinator,
at 7108 Werner Street, San Diego, CA 92122.
Send the following information with your request:
- Your first name, last name and callsign.
- Your full mailing address.
- The city where your TCP/IP station is going to be located.
- Whether or not it's a home or work location.
- The callsign of your home BBS.
- Your Internet address, if you have one.
FILES NEEDED
A copy of the HOSTS.NET file is also required. It's available for
downloading on many of the packet BBSs. Check for a TCP/IP directory using
the W command. If you can't locate the file, ask your local sysop for
assistance. The file is fairly lengthy, so plan on spending a little time
downloading it. The HOSTS.NET file is used by the NET software to look up
the IP address for each station you wish to contact, so you'll need it
before you go on the air with your TCP/IP station.
If you're using the PC/clone version of NET, I strongly suggest that
you also get a copy of the file BEGIN.DOC, written by Gary Ford, N6GF. It
explains what you need to do to set up your station in clear, easy to
understand terminology and then goes into details on all of the commands
used with the NET program. There is documentation that comes with the
software, but I found it to be difficult to understand in many places. It
also isn't as complete as Gary's and the descriptions of some of the
functions are missing. Gary's documentation takes all of the guess work
out of the process.
There are two other files you'll also find very helpful once you're up
and running. One is called FINGER.DOC, describing the user identification
application, and the other is BM.DOC, the "BM User Manual" by Dave Trulli,
NN2Z.
If you can't find the files, BEGIN.DOC, FINGER.DOC and BM.DOC locally,
send me a formatted disk with return postage and I'll be glad to make a
copy of the files for you. I can copy to 3 1/2" 1.44M or 5 1/4" 1.2M or
360K disks. My address is 4145 21st Street, San Francisco, CA 94114.
Continued in Part 2
INTRODUCTION TO PACKET RADIO - Part 17 - by Larry Kenney, WB9LOZ
PUTTING TCP/IP ON THE AIR - Part 2
HARD DISK SET UP
Before installing the program on your computer, special directories
need to be established on your hard drive for use by the TCP/IP program.
Under the root directory (C:\ on most systems) you need to make directories
titled FINGER, PUBLIC and SPOOL, as shown in the diagram. Under the SPOOL
directory you need to add four sub-directories called FOLDER, MAIL, MQUEUE
and RQUEUE.
\ (root directory)
|
|--FINGER
|--PUBLIC
|--SPOOL
|
|--FOLDER
|--MAIL
|--MQUEUE
|--RQUEUE
--The FINGER directory is used to identify users of your TCP/IP station.
The file FINGER.DOC explains the operation of the FINGER application and
the files needed in this directory. The files are NOT needed to put your
station on the air with TCP/IP.
--The PUBLIC directory, and any sub-directories you want to add to it, is
the area accessible to users of your station, similar to the files area of
your packet BBS. You can develope this area after you get on the air and
become familiar with TCP/IP operation.
--The SPOOL directory is used for your automatic station log.
--The FOLDER sub-directory is where files are storaged when you save any
messages as files.
--The MAIL sub-directory is where incoming messages are stored.
--The MQUEUE sub-directory is for outgoing messages.
--The RQUEUE sub-directory is for messages that have been received for
processing by a user-defined mail routing program. (I have no idea what
this is about. Nothing has ever ended up in RQUEUE on my station.)
FILES USED
Next, you need to make up a couple of files used by the NET program.
The documentation that comes with the program gives you examples of what
you need to enter in these files.
The first file is AUTOEXEC.NET, a series of commands and information
needed by the program. (This file should not be confused with your
AUTOEXEC.BAT file.) When the NET program first starts up it reads this
file and executes the commands contained in it, setting up the initial
configuration for your system. It sets the hostname, AX.25 parameters,
interfaces and other variables necessary for your particular station. Make
sure that you have the correct entry for the COM port you're going to use
for your TNC. Most enter "ax0" for COM1.
The next file you need to write is FTPUSERS. It establishes the access
levels for users of your station. Be very careful when writing the
information for this file or outsiders will be able to get into your
private personal files. It's not advisable to give permission above level
3, as outlined in the documentation.
Both of these files, AUTOEXEC.NET and FTPUSERS, the file HOSTS.NET, and
the files NET.EXE and BM.RC that come with the software package, are placed
in the ROUTE directory.
PUTTING IT ALL ON THE AIR
When you have all of the files saved to the proper directories you
should be ready to go on the air. Set up your radio for simplex operation
on the TCP/IP frequency in your area. Ask around locally for the frequency
used.
Using your normal computer terminal program, check your TNC to computer
baud rate and make sure that it matches the baud rate you entered in
AUTOEXEC.NET. Set DWait to 0, Persistence ON, and SLOTtime to 160 ms.,
then turn KISS ON. As explained earlier, the operation of KISS mode varies
from normal command usage, and even varies from TNC to TNC, so read your
TNC manual for details on the KISS command. With the AEA PK-232 you will
also have to turn HOST ON. Be careful that your terminal program doesn't
take you out of KISS mode when you exit it. Some do! I use Pro-Comm and
it works fine.
When the radio and TNC are ready, enter NET at the DOS prompt, cross
your fingers and see what happens. You should get the prompt "NET>". My
station came up on the first try! I hope yours does also.
To monitor the frequency, you will need to enter "trace cmdmode" <CR>
followed by "trace ax0 111" <CR> (ax0 is assuming COM1). These two
commands can be added to AUTOEXEC.NET if you want automatic monitoring.
That way you don't have to type it in each time you come on line.
The first thing you'll probably want to do is to see if eveything is
working okay. The easiest check is to make an AX.25 connection with
another station that you know is on frequency. Enter "connect ax0
<callsign>" <CR>, where <callsign> is the station you want to connect to.
For example, to connect to WB9LOZ you would enter: c ax0 wb9loz. If
everything is working as it should you will soon receive "conn pending"
followed by "connected". After spending all of your time and effort
setting up your TCP/IP program, you have now completed a normal packet
AX.25 keyboard to keyboard contact! To disconnect, use the F10 key to
escape back to the NET> prompt, and then enter "disconnect" or "d". (Most
of the commands can be abbreviated.)
If your station is working, congratulations! You now have the world of
TCP/IP awaiting you. Using the documentation provided with the software,
or better yet, BEGIN.DOC, you can now start checking out the various
commands. The TELNET and FTP commands are the two most frequently used for
contacting other TCP/IP stations, but I also find that using FINGER is fun.
Make sure you check the STATUS and TCP STATUS before going off line to make
sure all sessions have been completed. You'll be surprised quite
frequently to find other stations sending you messages, uploading or
downloading files, and you didn't even know they were connected.
There were a couple of things that I didn't understand when I first got
on the air with TCP/IP, so I'll pass those on to you now. To enter
messages or to read messages, you have to escape NET and then enter the BM
Mailer from the DOS prompt. To escape, you enter an exclamation point (!)
at the NET> prompt, then enter BM at the DOS prompt. When you're finished
with the messages, you enter "q" to get back to the DOS prompt and then
enter "exit" to resume operation of NET. To get out of NET completely,
you enter "exit" at the NET> prompt.
When you have things set up as you like them, send me a message and let
me know you're on the air (wb9loz%wb9loz@w6rfn). If you're in the Bay Area
we can meet for fun and games on Marc's system. Enter: "telnet noe.kg6kf
6715", and beware of the Wizard!
A new TCP/IP program called NOS is now in development and and many
stations are now using it successfully. Once you get on the air with NET,
you might want to upgrade to NOS in time. NOS is available for the
PC/clones by sending two 5 1/4" disks or one 3 1/2" 720kb diskette to W. E.
Moerner, 1003 Belder Drive, San Jose, CA 95120-3302 in a mailer with return
postage. NOS for the Mac is available from Doug Thom, N6OYU, (408)
253-1306, 1405 Graywood Drive, San Jose, CA 95129-4778. Amiga NOS is
available on Compuserve in Hamnet Library #9 or by contacting Chris, WA2KDL
@ K6VE.#SOCA.CA. UNIX and other operating systems can get the C code for
NOS from various internet ftp sites. Contact marc@noe.kg6kf for further
information (KG6KF @ K3MC.#NOCAL.CA on the BBS circuit).
Enjoy your TCP/IP experiences!
73, Larry, WB9LOZ
INTRODUCTION TO PACKET RADIO - Part 18 - by Larry Kenney, WB9LOZ
In this part of the series, let's do some reviewing. I'm going to present
a short quiz on packet radio covering the basics that I've presented in the
past 17 parts of this series. Let's see how well you can answer the following
questions without looking back for the answers. In Part 19 I'll discuss each
question and give you the correct answers.
1. What are the three TNC modes of communication?
a. Connect, Converse, Terminal
b. Command, Converse, Terminal
c. Command, Converse, Transparent
d. Command, Connect, Transparent
2. What TNC command is used to set the transmit path for beacons and CQs?
3. What is the TNC command CHECK used for?
4. While you're connected to another station, what command is used to
monitor other traffic on the frequency?
5. If you saw one of the following lines on your screen when in monitor
mode, what would the asterisk indicate?
W6ABC-3>N6XYZ,W6PW-1*: Hi Bob
W6ABC-3>W6PW-1*>N6XYZ: Hi Bob
(Displays vary with various TNCs, so both common types are shown.)
6. Why does the packet node network improve communications compared to
the use of digipeaters?
7. If you're connected to a station in New Mexico using the node network,
how do you disconnect?
8. If N6ZYX-2 connected to you via a node, what would the SSID of the
station become at your end of the connection?
9. When you're connected to another station, what are the two most
probable causes for packets to NOT be received by the other station?
10. There are several basic commands used on a packet bulletin board
system. Indicate what you would enter to perform the following:
a. Receive a list of messages.
b. Download a file in the General (ID G) directory called
FCCEXAMS.92.
c. Enter a personal message to Jim, WA6DDM, who uses the W6PW BBS
in San Francisco, California.
d. Read message 7134 with complete forwarding headers.
e. Find out what stations have been heard by the BBS on port B.
11. To send an NTS message via packet addressed to Tom Smith, 123 Main
Street, Keene, NH 03431, telephone (603) 555-4321, what would you
enter at the BBS prompt?
12. If a message has a STATUS of BF, what does that indicate?
13. If you received a message from a friend in Chicago that had been
forwarded to your home BBS through four other BBSs and the message
had a Date/Time of 0316/2245 when you listed it, which of the
following is a TRUE statement?
a. The message was written at 2:45 pm on March 16.
b. The message was entered into the BBS by your friend at 2245
on March 16.
c. The message was forwarded by your friend's BBS in Chicago at
2245 on March 16.
d. The message was received at your home BBS at 2245 on March 16.
14. If you wanted to send a message to your friend John, W4IP, but you
didn't know what the call of his home BBS was, what could you do to
try and find out what the call is?
15. What is the maximum value for MAXFRAME? If you're working a station
on 30 meters and are sending a lot of retries, should you increase or
decrease MAXFRAME?
Well, how did you think you did? We'll take a look at the answers to these
questions and more in part 19.
- - - -
INTRODUCTION TO PACKET RADIO - Part 19 - by Larry Kenney, WB9LOZ
How did you do on the review quiz in the previous part of this series?
If you haven't taken it, you might want to read part 18 and take the quiz
now before reading any further.
Here are the correct answers and the series part numbers where you can
read more about the subject:
1 - Answer C is correct. The three TNC modes of communication are Command,
Converse and Transparent. Command mode is for communicating with the TNC.
Converse mode is for normal QSOs, connects to a BBS or mailbox, etc. and
Transparent mode is used for binary file transfer. (Parts 2, 3 and 14)
2 - The UNPROTO command is used for setting the transmit path for both
beacons and CQs. (Parts 3 and 13)
3 - The CHECK command is used for setting a timeout value in your TNC.
If set to a value other than zero, the TNC will attempt to recover a
connection after a certain specified time if nothing is received from the
other station. This command is used in combination with the AX25L2V2
command. (Part 13)
4 - The MCON command (Monitor while CONnected) is used to monitor other
traffic on the frequency while you're connected to another station.
(Part 3)
5 - When monitoring, the asterick indicates the station that you actually
heard the packet from. The MRPT command must be ON for the monitor display
to show digipeaters. (Part 2 and 3)
6 - The packet node network improves communications because packets are
acknowledged between your station to the first node, and then node to node
to the destination. A packet doesn't have to reach the destination before
an ack is returned. (Parts 4, 10 and 11)
7 - When using the node network (no matter who you're connected to) you
disconnect by going to command mode on your TNC and entering a D, just like
at other times. The fact that you're using several nodes or are connected
to a distant station makes no difference. The network will take care of
disconnecting all stations and links. (Parts 4, 10 and 11)
8 - N6ZYX-2 would appear as N6ZYX-13 if he connects to you using a node.
The nodes change the SSID using the formula 15-N. (Part 10)
9 - The two most probable causes for a packet not to get through are
collisions with other packets on the frequency and noise due to weak
signals. (Part 15)
10 - BBS commands:
a. To receive a list of messages: enter L
b. To download a file in the General (G) directory called FCCEXAMS.92,
you'd enter DG FCCEXAMS.92 or D GENERAL FCCEXAMS.92 depending on the
software at the BBS you're using.
c. To enter a private message to Jim, WA6DDM: SP WA6DDM @ W6PW.CA
(The "@ W6PW" would not be needed if you were using the W6PW BBS.)
d. To read message 7134 with headers: RH 7134
e. To find out what stations were heard on port B of the BBS, you'd
enter JB
(Parts 5, 6, 7 and 8)
11 - If you wanted to send an NTS message to Tom Smith, 123 Main Street,
in Keene, NH 03431, you would enter the following at the BBS prompt >
ST 03431 @ NTSNH (Parts 6 and 12)
12 - A message with a STATUS of BF means that the message is a bulletin
and that it has been forwarded to all stations that are supposed to
receive it from the BBS you're using. (Part 8)
13 - Answer D is correct. The date/time shown on a message when it's
listed is the time the message was received at the BBS you're using.
Please note that this date and time is shown in whatever time the BBS
your using is set to. It could be local time or zulu time (UTC, GMT).
Most BBSs are now set to zulu time, but a few still use local time.
When you read a message, you're then able to read the date and time that
the message was written from the header.
(Part 8)
14-To find the call of the HOME BBS of your friends, use the White Pages
Directory. If the BBS you're using has the WP feature enabled, you'll
find the I command (or Q command on some systems) to be useful, otherwise
send an inquiry to WP. (Part 9)
15-The maximum value for MAXFRAME is 7. MAXFRAME is the number of packets
transmitted by your TNC contiguously, and the number of unacknowledged
packets the TNC can have outstanding. You decrease MAXFRAME when the
conditions are poor. Your TNC will send fewer packets at one time, so
there will be less information to collide with other packets on the
frequency and less chance of information being wiped out by noise.
(Part 14)
There is no passing grade on the quiz. It was designed for you to check
your general packet knowledge, and you'll have to be your own judge of that.
I hope you did well on it!
- - - -
INTRODUCTION TO PACKET RADIO - Part 20 - by Larry Kenney, WB9LOZ
In the previous 19 parts of this series, I have attempted to cover all of
the basics of packet radio - from setting up your TNC and making your first
QSO, to using digipeaters, the packet node network, bulletin board systems
and mailboxes. Many of the TNC commands have been explained, including the
best settings for normal use, I've introduced you to TCP/IP and I've offered
some suggestions that should make it easier and more enjoyable for you to
use packet radio.
Now that you have the basics, you might want to continue with your study
by investigating some of the other facets of packet radio. There are several
programs available that we haven't covered yet in this series that you might
find interesting. There's the Packet Cluster software used by the DX Spot-
ting Network, the NOS packages for TCP-IP, Tex-Net, Rose, Conference Bridging,
etc. PAC-SAT, the packet satellite program, is now growing in popularity as
more satellites carrying packet radio equipment are released. High speed
modems running at speeds of up to 56 kilobaud are just around the corner for
general use. What developments will be next?
I'd like to thank the following for help in preparing this series: Don
Simon, NI6A; Bill Choisser, K9AT; Don Fay, K4CEF; Scott Cronk, N7FSP; Roy
Engehausen, AA4RE and Hank Oredson, W0RLI. Their help in providing answers
to my questions is greatly appreciated.
If you have any comments on this "Introduction to Packet" series, want to
suggest new topics for inclusion in future articles, or want to correct or
update any of the information contained in the series, please send me a
packet message. I'd love to hear from you and your comments would be very
much appreciated. I hope that you've found the series to be informative
and helpful in making packet radio more enjoyable for you.
Enjoy!
73, Larry Kenney, WB9LOZ @ W6PW.#NOCAL.CA.USA.NA
San Francisco
- - - -
INTRODUCTION TO PACKET RADIO
BY LARRY KENNEY, WB9LOZ
INDEX
Subject Part Subject Part
A L
Awlen.................13 List Commands.........5,6
AX25L2V2..............13 M
B Mall..................3
BBS...................5,6 MaxFrame..............14
Beacon................13 Mcon..................3
Bye Command...........6,11 Message Nomenclature..8
Bulletins, Send.......6 Message Structure.....6
C MFilter...............14
Check.................13 MHeard................14
Cmsg..................13 Monitor...............2,3,6
Connect...............2 Mrpt..................3
Converse Mode.........2,3 Mstamp................3
CQ Command............11 Mycall................2
D N
Digipeaters...........4 National Traffic Sys..6,12
Disconnect............2 Node Commands.........10,11
Download Command......6 Node Network..........4
Dwait.................3 Nodes Command.........4
E P
Echo..................3 Packet Message Parts..8
F Packet Test...........16
File Directory Cmds...6 Packet Test Answers...17,19
Frack.................3 Packet Tips...........15
G Paclen................3
Gateways..............7 Parameters, TNC.......13,14
H Parms.................11
Headerln..............3 R
Help..................5,6 Read Commands.........5,6
Hierarchical Address..7 Retry.................3
I Routes................11
Ident.................11 S
Info Command..........6,11 Send Commands.........6
Introduction..........1 Status Command........6
J T
J Command.............6 TNC...................1,2
K U
Kill Commands.........5,6 Unproto...............3
Kiss..................13 Upload Command........6
Users.................11
V
Via...................2
W
White Pages...........9
8
Compiled by Hal Godfrey, N6AN 8bitconv..............13