AOH :: P12-05.TXT

The Total Network Data System

                               ==Phrack Inc.==

                     Volume Two, Issue 12, Phile #5 of 11

                        THE TOTAL NETWORK DATA SYSTEM

                               BY DOOM PROPHET

    The Total Network Data System is a monitoring/analysis network used by
several offices within the Telco to analyze various levels of switching
systems in relation to maintenance, performance, and future network planning
purposes. The systems and the offices that use them will be described in
detail in the following text.

    All switching entities that are in one particular serving area collect
traffic information that is classified in three ways: peg count, overflow, and
usage. Peg count is a count of all calls offered on a trunk group or other
network component during the measurement interval, which is usually one hour.
It includes calls that are blocked, which is classified as overflow traffic.
The other measurement types that the TNDS network analyzes and collects are as

    Maintenance Usage (for 1ESS, 2ESS, 5XB, 1XB, XBT)

    Incoming Usage (for 1E, 2E, 4AETS)

    All trunks busy (SxS)

    Last Trunks Busy (SxS)

    Completions (SxS, 5XB, XBT, 1XB)

    Incoming Peg Count (DMS)

    Maintenance Busy Count (2E, 3E)

    Detector Group Usage (SxS, 5XB, XBT, 1XB)

 In ESS and DMS offices, traffic data is collected by the central processor of
the switch. In electomechanical offices such as crossbar, a Traffic Usage
Recorder is used to scan trunks and other components about every 100 seconds,
counting how many are in use. This data when compiled is sent to the EADAS
system, which is located in the Operating Company's Network Data Collection
Centers and runs on a minicomputer. 4ESS and 4Xbar toll offices do not use
EADAS, but their own system called the Peripheral Bus Computer for traffic
data analysis. After receiving the traffic data from up to 80 switching
offices, EADAS performs two basic functions:  It processes some data in near
real time (shortly after it is received) to provide hourly and half hourly
reports and a short term database for network administrators. It also collects
and summarizes data that it will pass on to the other TNDS systems via data
links or magnetic tape.

    Three other systems receive directly from EADAS. These systems are ICAN,
TDAS, and EADAS/NM. ICAN stands for Individual Circuit Analysis plan and is
used to study individual circuits in central office equipment that have been
specified by network administrators.

    TDAS is the Traffic Data Administration System, which formats traffic data
for use by the remaining downstream systems. ICAN and EADAS/NM are the only
two systems with data links to EADAS that don't have their data formatted by
TDAS before reception. TDAS is run on a mainframe in the NDCC and can be
thought of as a distribution facility for the traffic data. EADAS/NM is used
to watch switching systems and trunk groups designated by network managers,
and reports existing or anticipated congestion on a display board at the
Network Management Centers, where the system is located. Problems can be
analyzed with this system and dealt with within a short period of time after
they occur.

    Central Office Reporting Systems

    There are five TNDS engineering and administrative systems that provide
operating company personnel with reports about CO switching equipment. These
are the LBS, 5XBCOER, SPCSCOER, ICAN, and SONDS. LBS, the Load Balance System,
helps assure that the customer traffic load is uniformly distributed over each
switching system. It minimizes congestion on the concentrators, which allow
subscribers to share the equipment in the switch. The LBS analyzes traffic
data coming to it from TDAS to determine the traffic load on each line group
that the system serves. LBS generates reports used by the NMC to determine
line groups that can have new incoming subscriber lines assigned to them. LBS
also does a load balance indexes for the entire operating company, indicating
how effectively each CO has avoided congestion.

    Crossbar #5 Central Office Equipment Reports (5XBCOER) and Stored Program
Control Systems COER used for 1, 2, and 3 ESS offices, analyze traffic data to
indicate the overall service provided by the switching system and to tell how
much of its capacity is being used. This info helps determine if new equipment
is needed.

    ICAN, which was described briefly above, detects switching system
equipment faults by identifying abnormal load patterns on individual circuits.
A series of reports printed at the Network Administration Center helps network
administrators analyze individual circuit usage and verify circuit grouping.
ICAN is located at the BOC main computer center along with 5XBCOER.

    The fifth CO equipment reporting system is called the Small Office Network
Data System, or SONDS. SONDS performs a full range of data manipulation
functions, and is used to provide economically the full TNDS features for step
by step offices. Step offices send data directly to this system, and it is not
formatted by EADAS or TDAS, as it doesn't go through these systems. Weekly,
monthly, exception and on demand reports are automatically distributed by
SONDS to the NAC personnel.

    Trunk Network Reporting Systems

    These systems are parts of the TNDS used by the Circuit Administration
Center to support trunk servicing and forecasting. The Trunk Servicing System
helps trunk administrators develop short term plans to make the best use of
the trunks that are already in use. It receives and processes data received
from TDAS and computes offered load. Offered load is the amount of traffic a
trunk group would have carried had the number of circuits been large enough to
handle the load without trunk blocking (giving the caller a re-order or all
circuits busy recording). TSS produces weekly reports showing underutilization
of trunks and below grade of service trunk groups which do not have enough
trunks in them. The CAC uses these reports to add or disconnect trunks
according to what traffic requirements exist.

    The Traffic Routing and Forecasting System, replacing the Trunk
Forecasting System, forecasts message trunk requirements for the next five
years. Major conversions and similar network changes are all taken into
consideration when determining the future traffic needs. TRFS receives data
from EADAS, TDAS, and TSS and is located at the Operating Company computer

    Since TDAS and some of the downstream TNDS systems need much of the same
information, that information is maintained in a system called Common Update.
In this manner, some data does not have to be duplicated in each individual
system. Some of the information includes the configuration of switching
equipment and the trunk network and specifications on traffic registers for
central offices. Numbers recorded by each register are treated consistently by
each system that uses the Common Update data base. There is an update base for
trunking, referred to as CU/TK, and an update on equipment known as CU/EQ. The
trunking part of the Operating Company's data base is coordinated by the Trunk
Records Management System.

    Since the TNDS systems are so important to the proper operation of the
network, the CSAR (Centralized System For Analysis and Reporting) is used to
monitor the entire TNDS performance. The NDCC, the NAC, and the CAC are
provided with measurements of the accuracy, timeliness, and completeness of
the data flow through TNDS from beginning to end. It doesn't analyze data from

    BOC Operations Centers

    NAC-Network Administration Center. Responsible for optimum loading, and
utilization of installed COE. Performs daily surveillance of COs and trunk
groups to ensure service objectives are being met. The NAC Reviews profiles of
office load relating to anticipated growth. They work with NSEC to initiate
work orders to increase equipment in use. The systems they use are EADAS,

   NMC-Network Management Centers. The NMC keeps the network operating
efficiently when unusual traffic patterns or equipment failures would
otherwise result in congestion. The NMC analyzes network performance and
prepares contingency plans for peak days, telethons, and major switch
failures. They monitor a near real time network performance data to identify
abnormal situations. The system they use is EADAS/NM.

    CAC-Circuit Administration Center. The CAC ensures that in service trunks
meet current as well as anticipated customer demands at acceptable levels of
service. For planned servicing, the CAC compares current traffic loads with
forecasted loads for the upcoming  busy season. If the loads are consistent,
the CAC issues the orders to provide the forecasted trunks. When
inconsistencies occur, they examine the variation, develop modified forecasts,
and issue orders based on the new forecast. They review weekly traffic data to
identify trunk groups that need additions and issue the necessary trunk
orders. The systems they use are TSS, TRFS, and CSAR.

    NSEC-Network Switching Engineering Center. They plan and design the
network along with the CAC. NSEC develops a forecast of loads for traffic
sensitive switching equipment, sets office capacities, and determines relief
size and timing.

    For long range planning, the following offices are utilized.

    TNPC-Traffic Network Planning Center. The TNPC determines the most
economic growth and replacement strategies. They handle future network
considerations over a 20 year period for tandem systems, operator services
networks, interconnecting trunks, and switching terminations to accommodate
the trunks.

    WCPC-Wire Center Planning Center. This office does the same as the TNPC,
but their jurisdiction includes local switches, the subscriber network, and
interoffice facilities. They have the numbers, types, and locations of
switches and homing arrangements. They also keep track of alternate routes,
tandem centers, etc. Both the TNPC and WCPC provide the CAC and NSEC with
office and network evolution plans for 20 years.

    District based maintenance and administration operations are handled by
the NAC, RCMAC, and the SCC. These can cover 240 square miles of serving area.

    Network Operations Centers

    The highest level of network operations is the Network Operations Center,
located in the AT&T Long Lines HQ in Bedminster, NJ. The main computers used
by the NOC are in Netcong, about 25 miles away, along with some backups. The
NOC are responsible for interregional coordination between the 12 RNOCs, 27
NMCs, and 2 RNMCs in Canada; for monitoring the top portion of toll switches
(all class 1 Regional Centers, 2 Canadian, about 70 class 2 Sectional Centers,
200 Primary centers, some class 4 Toll centers); for monitoring of the
international gateways, and the CCIS network for these switching systems. The
STP signalling links connect STPs to each other, to switches, and to a
centralized database called an NCP (Network Control Point) of which access is
given to switches directly via CCIS.

The Data Transfer Point, which is a data switch that furnishes the NOC with a
flow of monitoring information for all key toll switches, also gives them
information about CCIS STPs and the IOCCs that they monitor.

    The operating system supporting the NOC is the NOCS (the S being System),
which is configured with the DTP, a wall display processor, graphics
processors, receive only printers, and CRT terminals for the technicians. The
NOC also uses EADAS/NM through the DTP. Both the NOCS and the DTP run Unix
operating systems.

    The second highest level of these operations centers are the RNOCs, or
Regional Network Operations Centers. The 12 RNOCs monitor the CCIS network and
coordinate the 2-3 NMC's activities for its region. The RNOCs use the EADAS/NM
system and something called NORGEN, Network Operations Report Generator, that
prints out reports from EADAS's traffic data.

    The first or lowest level of these centers is the Network Management
Centers. There were 27 EADAS/NM supported NMCs across the United States as of
1983. The NMC was described above, as well as the systems it used.


    Some of this information was taken from Bell System publications and from
trashed materials, and may not be the same for every area. All material is
correct to the best of the author's knowledge. Thanks to The Marauder for
supplying some information. This file was written for educational purposes

-End Of File-

                             Written March, 1987

AOH Site layout & design copyright © 2006 AOH