Using the Wisconsin Network - Part 35
                 by Andy Nemec, KB9ALN

     Packet Radio, since it's inception, has undergone a
considerable amount of change. The first big leap after
Digipeating was the BBS. Net/Rom (TheNet), TCP/IP, APRS, and
promises of more yet have been slowly appearing. Now we are
starting to see even more change, and the latest evolution of
packet radio is not without controversy. In the next few series
of articles, we will explore the Internet Gateway to discover
it's draw and see why it has been the target of so much
controversy.

    Defining an internet gateway can be confusing to some folks
- there is some new terminology, and before we go further, we
had best define what a gateway is and it's close cousins.

     An interactive gateway allows users to connect to the internet
through packet radio and utilize the many services found there.
In some cases, access is limited to "Amateur Only" sites, still
others will allow full access (well, all except the sites that
are not appropriate for the air).

    This gateway also will go "the other way". Users can log in
via the Internet, and have access to the radio network. Potential 
packeteers can get a taste of this mode before they lay out
money for this equipment.

     This type of gateway usually greets the logged-on user with a
conventional BBS interface. Most of these gateways use TNOS or
JNOS to perform the linkage to the Internet. Aside form the BBS
commands you are used to seeing (like Send, Read, Kill, List,
etc.), there will be a few unfamiliar ones (like telnet).

     Most interactive gateways will support AX.25, Net/Rom
(TheNet), TCP/IP and round-table discussions, similar to
the "Internet Relay Chat". You may send and receive E-Mail
through the internet, through the BBS network, connect up to
distant Amateur sites on the internet, and use it as a
conventional Network Node on radio or the internet. In that
sense, the commands mirror the nodes that you are used to.

     Some of these interactive gateways also provide this
"wormhole" service that treats a distant node as just another
node on the network. New York becomes just as local to the 
network as "the next town over" when using a wormhole in this
manner.

     Another type of gateway is the dedicated point-to-point
wormhole gateway. Unlike a fully interactive gateway, it is 
limited to providing this "wormhole" service only and is not
intended to provide users with full access to the internet. It
becomes a bridge to complete a radio network. For example,
there could be a wormhole between a system in Milwaukee and one
in Florida. The goal is a seamless linkage between two user
LANs in different parts of the country. This has generated a
bit of controversy, as the Tuscon Amateur Packet Radio
Association (TAPR) has been promoting the idea of using the
internet to complete the national packet radio network in this
manner.

    Mail Forwarding Gateways do not provide real-time access to the
internet, and it does not complete a radio network on a
real-time basis. Rather, it is used by two BBS's to exchange
mail via the internet. Most often, his is used when radio paths
are unreliable or unavailable. This practice has been the subject of
controversy as well. While we will not attempt to
enter the controversy in this column, the explanation should
help you understand what each service is and may help you
understand the debate better.

     Now that we know what types of gateways have found use, we
can talk about how they are constructed. It is not too hard to
understand, but it is not your typical packet station. Let's talk
about the first case, a fully interactive internet gateway.

     Any type of gateway is constructed with two or more
"ports". One will go to the internet and may well be a phone
modem, or it could be a network "ethernet" card hooked up to
some kind of network that eventually reaches the internet
In any case, this port allows an interface with the internet.

     The other ports are connected to a node stack, or
become a node stack. It is possible for one of these
computers to act as a full node and network router. In the case
of the machine being tied to a node stack, the serial port of
the computer is "multiplexed" into the serial ports of the
TNC's. This is the same situation as a normal node stack - the
computer is just treated as another TNC.

     In the case of the computer performing the task of a node
stack, the TNC's are connected to serial ports of the computer.
The TNCs operate in KISS mode and the computer software does
all of the work normally reserved for the node firmware. 

     From there, the rest of the node stack - radios, antennas,
etc - are the same as in a conventional node stack. So the
internet gateway can either replace the normal node firmware,
or augment it.

     Now that we have our look at gateways, we will further
explore how to use them in the next installment of "Using the
Wisconsin Network". Until then, 73 from Andy.