Nortel DMS-100 Office Parameters Overview

Introduction

Office parameters are initially set by Northern Telecom (Nortel) to meet end-of-design criteria and switch configuration.  This overview is intended to assist operating company personnel responsible for administering office parameters by providing guidelines to using the available tools.

Office parameters examined in this document are located in table OFCENG (Office Engineering).  These parameters allocate resources (memory) for switch activities such as call throughput and custom calling usage.  These parameters are initially calculated using operating company input, high day/end-of-design criteria, and standard engineering formulas.  The formulas are designed for standardization and simplified operating company and Nortel use.  The formulas are constructed to cover a wide variety of applications and are considered set up for end-of-design for most applications.

An ongoing process should take place to determine if parameter settings are appropriate for each office's requirements.  This process should include the monitoring of actual parameter usage compared to the parameter setting in the switch.  Offices may have to adjust individual parameter settings to match the changing office requirements.

Offices not at the end-of-design could reclaim memory for a period of time by reducing office parameter settings.  Caution should be used in lowering office parameters to prevent impact to switch operation during high-day operation.  Some parameters are not recommended for value reduction.  See the section "Office Parameters that are Not Recommended to be Modified".

Memory allocated for office parameters can be reclaimed during the software delivery by way of dump and restore if the decision is made to lower office parameters.  However, office parameter changes should be safely and systematically implemented before a dump and restore.

What to Collect

The following data should be collected to determine the usage of many of the office parameters in table OFCENG:

Operational Measurements

The Operational Measurements (OM) and especially the high watermark OMs can be used as a bench mark of the levels of traffic-dependent activity in the switch during the current interval.  The high watermark OMs display the highest level of simultaneous usage reached in critical office parameters for the collection period.  Overflow OMs display the number of times that the parameter was required but no resources were available.

The following OM groups should be monitored:

CP2 measures Call Processing software resources such as call processing letters, call condense blocks, and wakeup blocks.  EXT measures Extension Block usage such as special billing records, data extensions for operator services, and custom calling features.  FTRQ measures Feature Queuing Resources for Meridian Digital Centrex (MDC) features such as call hold, last number redial, and call waiting.  Refer to the Operational Measurements Reference Manual for information on the registers and corresponding office parameters measured.

An OM accumulating class made up of CP2, EXT, and FTRQ should be defined with the same collection period as office parameter OMXFR in table OFCENG.  When datafilling tables OMACC and OMPRT, field WHEN set to AUTO guarantees this.  The collection period and transfer period should be the same to ensure that the high watermark registers present a valid picture of peak activities.  With a 1-hour collection period and a 30-minute transfer period, the peak levels are summed.

The following is an example of setting up an OM class that contains OM groups EXT, CP2, and FTRQ.  The symbol ">" represents commands to be entered.

The OM class to be defined is called REALTIM3.  Double precision is used.

>OMCLASS REALTIM3 DOUBLE

List table OMACC to see the tuple added.

>LIS ALL

The table is listed. Position on the newly added tuple.

>POS REALTIM3
CLASS     ENABLED   WHEN 
REALTIM3  N         AUTO

Change the tuple.

>CHA
ENTER Y TO CONTINUE PROCESSING OR N TO QUIT.
>Y
ENABLED: N
>Y
REP: AUTO
TUPLE TO BE CHANGED:
REALTIM3 Y AUTO
ENTER Y TO CONFIRM, N TO REJECT OR E TO EDIT.
>Y
TUPLE CHANGED. WRITTEN TO JOURNAL FILE AS JF NUMBER 544
>QUIT
CI:

Add OM groups to the OM class.

>OMACCGRP REALTIM3 ADD GROUP CP2
OK
>OMACCGRP REALTIM3 ADD GROUP FTRQ
OK
>OMDUMP CLASS REALTIM3 COMMANDS
OMCLASS REALTIM3 DOUBLE 
OMACCGRP REALTIM3 ADD GROUP CP2 
OMACCGRP REALTIM3 ADD GROUP EXT 
OMACCGRP REALTIM3 ADD GROUP FTRQ
>TABLE OMPRT
TABLE: OMPRT
>LIS ALL

Table OMPRT is listed.  Position on an unused position.  Position 228 is chosen in this example.

>POS 228

Change the tuple.

>CHA
ENTER Y TO CONTINUE PROCESSING OR N TO QUIT
>Y
ACTIVE: N
>Y
SUPZERO: N
>
ID: ALL
>ALLCLASS
CLASS:
>REALTIM3
REP: MONTHLY
>AUTO
BUFFOUT: N
>
OUTDEV: SINK
>
TUPLE TO BE CHANGED:
228  Y N ALLCLASS REALTIM3
AUTO N SINK
ENTER Y TO CONFIRM. N TO REJECT OR E TO EDIT.
>Y
TUPLE CHANGED
WRITTEN TO JOURNAL FILE AS JF NUMBER 547
>QUIT
CI:
>LOGUTIL
LOGUTIL:
>ADDREP TATSPRT OMPR 228    Note: TATSPRT is a local printer defined for this example.
1 report(s) Added
>LISTROUTE DEVICE TATSPRT
Device TATSPRT print classes:
ADD REPORTS:
OMPR 228 (OM REPORT)
DELETE REPORTS:
>STARTDEV TATSPRT
Log device TATSPRT has been started.
Number of devices started : 1
>STOPDEV TATSPRT
Log device TATSPRT has been stopped.
Number of devices stopped : 1

DMSMON

DMSMON is used to gather switch data as well as high watermark OMs.  The switch data can be used in calculating office parameters in place of the engineering estimates used at initial load time.

DMSMON uses OM results as inputs for the DMSMON high watermark report.  DMSMON itself keeps a running tab of a subset of parameter high watermarks over a 30-day period.  For the parameters that are currently reported by DMSMON, this report is the easiest for the administrator to use.  However, since all the high watermark OMs are not included in DMSMON, the OM groups mentioned previously should be collected.  Also, parameter overflows are not reported in DMSMON output, only in the OM groups.

The following command produces the needed DMSMON information from the CI level of the MAP display:

>DMSMON
>HIGHPARMS

The following DMSMON example shows a subset of actual counts of switch data and high watermarks for office parameters:

-----------------------------------------------------------------------------------------
Number of nodes: 379
Number of networks: 0

Number of TM8 PMs: Insv: 3 Comm : 0
Number of MTM PMs: Insv: 53 Comm: 0
Number of LGC PMs: Insv: 12 Comm : 0
Number of LCM PMs: Insv: 48 Comm : 0
Number of DTC PMs: Insv: 13 Comm : 0
Number of DP_POTS lines: 3 
Number of DGT_POTS lines: 15 
Number of DP_IBN lines: 185 
Number of DGT_IBN lines: 2835 
Number of TOTAL_UNEQ lines: 15962 
Number of TOTAL_OFFL lines: 5373 
Number of PPHONE_STATION lines: 152

Number of DISPLAY_PPHONE_STATION lines: 35 
Number of M3009_STATION lines: 6705

Number of M5112_STATION lines: 618 
Number of M5209_STATION lines: 144 
Number of M5312_STATION lines: 37 
Number of DNs on keysets: 35403 
Number of IBN lines with CALL WAITING FEATURE: 8
Number of IBN lines with CALL FORWARDING FEATURES: 508 
Number of IBN lines with SPEED CALL FEATURE: 225 
Number of KSET lines with CALL WAITING FEATURE: 4 
Number of KSET lines with CALL FORWARDING FEATURE: 6613 
Number of KSET lines with SPEED CALL FEATURE: 6327 
Number of trunks: 4704 
Number of unequipped trunks: 10655 
Number of offline trunks: 554 
Number of trunk groups: 715 
Number of IBNTI trunks: 893 
Number of IBNTO trunks: 334
Number of IBNT2 trunks: 49 
Number of OP trunks: 52 
Number of RCVRMF receivers: 8 
Number of RCVRDGT receivers: 4 (expected:8) *****

Number of RCVRATD receivers: 32 
Number of CF3 ports: 70 
Number of CF6 ports: 83 
Number of LTUs: 6 
Number of TTUs: 5 
Number of VDUs: 39

Number of customer groups: 253 
Number of consoleless customer groups: 250 
Number of customer subgroups: 2 
Number of attendant consoles: 30
-----------------------------------------------------------------------------------------

Tables of Daily Usage for Critical Office Parameters

The following partial report shows 20 days of high watermark values with the most current one (yesterday) being printed first.

-----------------------------------------------------------------------------------------
Example 1
NUMCPLETTERS   NCCBS   NUMCALLPROCESSES   NUMOUTBUFFS   NMULTIBLKS   NUMCPWAKE
-----------------------------------------------------------------------------------------
13             97      4                  51            2            6
12             105     4                  51            3            3
17             914     4                  51            13           28
18             908     4                  51            16           32
16             893     5                  51            14           29
14             761     5                  51            11           27
13             63      4                  51            2            4
12             70      4                  51            3            7
12             85      4                  51            3            8
12             457     4                  51            7            19
18             504     4                  51            9            18
11             435     4                  51            8            19
12             273     4                  51            5            13
12             63      4                  51            3            4
12             66      3                  51            2            4
12             80      4                  51            3            8
12             512     4                  51            9            21
14             796     5                  51            12           31
23             941     5                  51            15           50
16             874     5                  51            13           31
-----------------------------------------------------------------------------------------
-End-
-----------------------------------------------------------------------------------------
Example 2
FTRQAGENTS  FTRQ0WAREAS   FTRQ2WAREAS   FTRQ4WAREAS   FTRQ8WAREAS   FTRQ16WAREAS
-----------------------------------------------------------------------------------------
9435        0             3437          6230          0             0
9437        0             3511          6179          2             1
9451        0             3862          6120          12            3
9445        0             3865          6185          11            3
9459        0             3784          6330          14            2
9451        0             3587          6360          10            2
9435        0             3334          6361          0             0
9436        0             3345          6342          0             0
9435        0             3377          6337          0             0
9443        0             3469          6359          7             2
9441        0             3458          6390          7             2
9440        0             3456          6396          6             3
9437        0             3458          6327          8             3
9430        0             3451          6283          0             0
9430        0             3454          6271          0             0
9429        0             3450          6265          0             0
9439        0             3582          6261          4             2
9435        0             3796          6174          10            3
9438        0             3935          6090          14            3
9433        0             3923          6090          16            2
----------------------------------------------------------------------------------------
-End-

Table OFCENG

Table OFCENG lists the setting of parameter values.  This table should be listed to provide the parameters to be considered and their current settings.  The table can be listed with the following CI command:

>TABLE OFCENG;LIST ALL;QUIT

The following example shows a subset of table OFCENG:

-----------------------------------------------------------------------------------------
Parameter Name                                        Parameter Value
-----------------------------------------------------------------------------------------
ACD_MIB_OUT_EVENT_BUFFER_SIZE                         110 
ACD_TOLL_DELAYED_BILLING                              N 
ACT_MAX_DURATION                                      255 
ALL_ACD_LOGIN_IDS_VALID                               Y 
ALT_TTT_USAGE_PERCENTAGE                              50 
AMA_FAILURE_FREE_CALL                                 Y 
AMA_LONG_DUR_AUDIT_INTERVAL                           24 
ATTLOG                                                1000 
AVG_NUM_TGS_PER_OHCBQCALL                             4 
BELL_ANI_ALARM_ID                                     9 
BELL_ANI_INTERCEPT_ID                                 9
CABLE_LOCATE_TIMEOUT                                  180 
CABLE_SHORT_TIMEOUT                                   180 
CC_ENGLEVEL_WARNING_THRESHOLD                         77 
CFD_EXT_BLOCKS                                        3500 
CFW_EXT_BLOCKS                                        350 
COINDISPOSAL                                          IGNORE_COIN 
COMMAND_SCREEN                                        Y 
COPP_RELAY_OPEN_TIME                                  80 
CPSTATUS_SWITCHABLE                                   Y 
CBLINK_ALARM_THRESHOLDS                               30 60 
CUSTOMER_GROUP_IBNGRP_OM_COUNT                        512
DATA_COS                                              0 
DEBUG_HUNT_SWERRS                                     N 
DEFAULT_CARRIER_OR_TREAT                              C 288 
DEFAULT_COMMANDCLASS                                  0 
DEFAULTLANGUAGE                                       ENGLISH 
DISC_TIME_BILLED                                      Y 
DISCTO_TIMEOUT_VALUE                                  13 
DM_PCM_ENCODING                                       DM_MU_LAW 
DTER_AUTO_DEACTIVATION_ENABLE                         Y
EA_CCIS6_TANDEM_BILL                                  N 
EA_OCS_AND_DP_OVLP_NEEDED                             N 
EA_OCS_DIGCOL_METHOD                                  PXFALL 
EA_OVERLAP_CARRIER_SELECTION                          Y 
EA_WITH_CD                                            N 
EADAS24H_BUFFER_SIZE                                  7100
EADAS30M_BUFFER_SIZE                                  32000 
EADAS60M_BUFFER_SIZE                                  7100 
EBS_BUZZ_SPLASH_ON                                    Y 
EBS_TO_TRUNK_TRD_TIME                                 50 
ENHANCED_DEAD_SYSTEM_ALARM                            Y 
EXPIRED_PASSWORD_GRACE                                3
-----------------------------------------------------------------------------------------
-End-


How to Interpret What is Collected

The OMs provide an indication of overflows.  If there are insufficient resources for a given office parameter, the OMs indicate this with an overflow peg.  Parameter usage should be monitored in all offices, not only those interested in reducing office parameters for the purpose of memory reclamation.

When examining registers FTRQHI and FTRQSEIZ of OM group FTRQ and the FTRQ entities in DMSMON HIGHWATER, it should be noted that these parameters reflect the number of blocks simultaneously in use.  The corresponding FTRQ office parameters reflect the number of blocks allocated in multiples of 10.  For example, a setting of 300 for office parameter FTRQAGENTS allows for a FTRQAGENTS high watermark of 3,000.  This multiple of 10 factor applies only to FTRQ parameters (that is, FTRQAGENTS, FTRQAUDIT, FTRQ0WAREAS, FTRQ2WAREAS, FTRQ4WAREAS, FTRQ8WAREAS, FTRQ16AREAS, FTRQ32WAREAS, FTRQ0WPERMS, FTRQ2WPERMS, FTRQ4WPERMS, FTRQ8WPERMS, FTRQ16PERMS, and FTRQ32PERMS).

The following example shows that FTRQAGENTS is set to 1261 in table OFCENG.  This setting allocates 12,610 FTRQAGENT blocks as indicated in field FTRQOM_INFO in the OM group FTRQ.  For the sample period, the high watermark, field FTRQHI, indicates a maximum of 6,137 feature queue blocks in simultaneous use.

CI:
>TABLE OFCENG : POS FTRQAGENTS
TABLE: OFCENG
FTRQAGENTS 1261
>LIS 10
PARMNAME PARMVAL
FTRQAGENTS 1261
FTRQAUDIT 10
FTRQOWAREAS 1
FTRQ2WAREAS 1575
FTRQ4WAREAS 799
FTRQ8WAREAS 800
FTRQ16WAREAS 1
FXOGS_REMBSY_BITS A_OFF_B_OFF_HK
GLOBAL_CUTOFF_ON_DISCONNECT Y 80 N
GROUND_START_DELAY Y
>OMSHOW FTRQ HOLDING
FTRQ 
CLASS: HOLDING 
START: 1990/01/12 14:00:00 FRI: 
STOP: 1990/01/12 14:15:00 
SLOWSAMPLES: 9 : 
FASTSAMPLES: 90 :

KEY (FTRQOM_TUPLE_KEY) 
    INFO (FTRQOM_INFO) 
       FTRQSEIZ     FTRQOVFI

FTRQHI 
0 FTRQAGENTS 
        12610 
	  369       0           6137 

1 FTRQOWAREAS 
           10 
	    0       0           0



2 FTRQ3WAREAS 
        15750 
	  509       0           3394 

3 FTRQ4WAREAS 
         7880 
	  238       0           2828 

4 FTRQ8WAREAS 
         8000 
	   72       0           30 

5 FTRQ16WAREAS 
            10 
	     0      0           0

Referring to the tables in Example 1 and Example 2, the high watermarks can be interpreted.  The last 20 days of high watermarks are displayed.  For FTRQ4WAREAS, 6,396 is the highest value displayed.  For this office, parameter FTRQ4WAREAS in table OFCENG is set to 693.  Accounting for the factor of 10, this allows for 6,930 blocks.  Operating company personnel may decide to raise this parameter since the high water value is so close to the parameter setting.

For parameter NUMCPWAKE (number of call processing wakeups), 50 is the highest 20-day value.  For this office, parameter NUMCPWAKE in table OFCENG is set to 425.  Assuming the high day for this event is during the sample period, the operating company may decide to lower the parameter slightly to recover memory, or leave the parameter set as is.

As can be seen in the above two cases, if the value is increased or decreased, office memory is impacted.  If a parameter value is increased and made active, more memory is allocated for that resource from spare or not in use pool of office memory.  On the other hand, if a parameter value is reduced, made active, and taken through the dump and restore process, office memory is returned to the spare pool of memory.  Complete memory reclamation cannot take place without a dump and restore.

How Often to Collect

It is imperative that the operating company monitor the actual usage regularly to account for high day busy hour for each of the critical office parameters and changing calling traffic patterns.  Each of these factors should be taken into account to establish the time interval for examining OMs.

High day busy hour for each event must be considered.  The high day busy hour for POTS features may be very different than that of Meridian Digital Centrex features.  Based on this criterion, usage must be monitored based on the office parameters being analyzed.  For example, CFW_EXT_BLOCKS allocate the number of simultaneous active call forwarded calls.

Traffic patterns can change dramatically over time, and therefore, the actual usage could fluctuate dramatically.  Actual usage must be monitored on a regular basis to determine if trends are evolving.  The decision to collect daily, weekly, or biweekly is the decision of the individual operating company.

How to Make a Decision

Criteria must be chosen to decide whether to lower or raise parameter values.  An operating company engineer can choose criteria such as never reducing a given office parameter at all or never reducing an office parameter below three times (or more) the highest ever high watermark.

Lowering office parameter values should be carefully considered.  In general, Nortel does not recommend lowering office parameter values unless office memory is in jeopardy.

Factors such as planned large office additions and office history play an important role in deciding how large a buffer to add to the office data.  The operating company is responsible for determining howlarge to make the buffer above the high watermark OMs.  It is strongly recommended that the office be monitored for many months before making a decision.

Most operating companies will probably decide never to reduce office parameter values, unless office memory is exhausted.

Office Parameters that are Not Recommended to be Modified

In general, the memory-allocating office parameter values in table OFCENG can be considered for lowering.  However, Nortel does not recommend changes to the following parameters.  Any changes are made at the operating company's discretion.

Reducing Office Parameter Values

The preferred method of implementing office parameter reductions is to gradually make changes in the existing office parameter tables, performing the necessary restarts as required during very low-traffic times.  Changing two or so parameter values downward at a time, then verifying that the changes had no adverse effect is the safest way to implement reductions.  Possible problem variables are kept to a minimum and a known safe fallback is available.  If troubles do arise, reverting back to the old values can be done quickly.  The OMs should be monitored closely to ensure proper engineering.  All changes should be made at least three weeks prior to the dump and restore or One Night Process (ONP).  At least three weeks is required to allow the software delivery process to capture the new values.

Memory is not reclaimed until the dump and restore is performed.  At that time, the reduced values are copied from the existing load into the new office load.

If parameter reductions are required, the operating company should communicate their intentions and work with the Nortel regional software systems engineering manager.


Increasing Office Parameter Values

Increasing parameter values is a safer process than reducing them.  The major issue with increasing parameter values (other than timing related parameters) is the increased memory requirements.  Unlike reducing parameter values, memory is utilized immediately upon activation (usually a cold restart).  Often, parameters in table OFCENG require more memory when increased.  The memory requirements for parameters are in the data store area for NT40 loads, but in total office memory for SuperNode loads, where there is no distinction between data and program store.

A basic outline of when values should be increased follows:

  1. Determine actual spare memory available in the switch.
  2. Determine the established memory requirements indicated by the required parameter value increases.
  3. Analyze and determine if the amount of increased memory does not exceed the amount of memory spare and available for use.  Keep in mind the Nortel and individual operating company requirements for spare memory overheads.  Reference "SEB 88-01-002" or contact a Nortel regional software systems engineering manager to aid in this task.  After a determination has been made that the increased values will not exceed memory limitations including spare or overhead requirements, a safe implementation process can begin.
  4. If only two or three parameter values are to be increased, all could be done at the same time, with the monitoring of parameters and memory after the change.  If larger numbers of parameters values need to be increased, a staged increase should be implemented.  Monitor two or three parameter changes and if all is well and memory usage is safe, move forward with others.

Notifying Nortel

To ensure propagation to future software releases of decreases made to office parameters, the operating company must contact their regional software systems engineering manager with a single point of contact at the operating company.  The contact should be able to approve of any changes to the office parameters for a given office.

Nortel engineers office parameters based on operating company input and standard formulas.  A wide variety of applications are covered by the standard formulas.  These formulas yield a safe value in nearly every office.  The operating company should monitor the office parameter usage on an ongoing basis to determine if the parameter settings are appropriate for the office application.

Any changes made to the office parameters discussed in this document result in a change in the memory allocated in the switch.  An increase in a setting requires more memory.  A decrease in value decreases memory requirements.  A decrease in a parameter value only yields an actual memory decrease if a rebuild (that is, a dump and restore) occurs.