-=- The Empire Times -=-
                            Issue 5, File 2 of 8
                    DMS Family of Digital Switching Systems
                                by Erudite

In this Infoarticle I hope to cover the capablities and flexabilities of
all the DMS Digital Switching Systems, I will also talk about other
Northern Telecom Devices and Systems. The majority of the file is based
on the DMS-100 system.

First we have breif descriptions of the DMS Switches:

DMS-10
------
This is a versatile switch which is cost-effective for the duties that
it was created for.  It is a digital switch that services suburban and
rural areas.  It is in service internationally as well as in the US
(rural and suburban areas).  It allows access to local and long-distance
service.  It can handle up to 12,000 subscribers.  It is the smallest of
the DMS family.

DMS-100
-------
The purpose of the DMS-100 Switch is to provide coverage and connections
to the public network.  It is designed to deliver services over subscribers
lines and trunks.  It provides POTS (Plain Old Telephone Service), along
with very sophisticated business services such as ACD (Automatic Call
Distribution), ISDN (Integrated Service Digital Network), and MDC (Meridian
Digital Centrex).

DMS-200
-------
The DMS-200 switch has toll capabilities, it is used for toll-center
applications.  It provides TOPS (Telephone Operator Position System) which
is the world's premier operator service, from Northern Telcom.

DMS-100/200
-----------
Simply, this combines the DMS-200 Toll capabilities and applications, with
the DMS-100 public networking, which makes it possible for this switch to
service subscriber lines, long distance circuits with toll applications.

DMS-250
-------
This is the long distance tandem switch that connects long distance calls.
It is used by the interexchange carriers.  It is powerful, and they are
used to connect most of the U.S. population.

DMS-300
-------
This is the international exchange, which gates calls internationally.
It provides the most advanced range of international services.  This
international digital switch can interface with almost *any* country in
the world.  Talk about power.  It is known as the International Gateway
System.

DMS-Supernode
-------------
This is faster, and can handle more throughput that the DMS-100.

DMS-Supernode SE
----------------
This is a reduced size Supernode system, it has a DMS-Core processing
engine, DMS-Bus high-speed messaging component, the Link Peripheral
Processor (LPP), and the Enhanced Network non-blocking switching network
(ENET), which makes it a cost effective system, combined all into one
compact unit.

DMS-MTX Cellular Switch
-----------------------
Northern Telcom's Cellular Switch.  The DMS-MTX was the first cellular
switch in Northern American to offer subscribers.


       DMS Architecture & Functionality

Messaging - "DMS-Bus" is the high speed data bus connecting most components
  of the switch.  This makes the DMS-Supernode system a true step up
  communications platform.
Switching - The switching matrix calls to their destination.  Currently
  in planning is future switching fabrics that will allow for broader
  data applications, including (ATM) Asynchronous Transfer Mode.
Maintenance & Billing - The DMS Systems provide full feature testing, and
  other transaction and maintenance procedures.
Multicomputing platform - The DMS systems enables a high capacity, and other
  "information" age applications and functions.  Such as Videoconferencing,
  transmission of imaging, and dialable ds-1 backup.


       DMS Family Setup

Below will be a simple, common setup of dms systems to form a wide range
communications system.



 DMS-100 -----------------  DMS-200   ----------------- DMS-250
(end office)            /(Tandem office)             (ld services)
                      /                                   |
                    /                                     |
                  /                                       |
                /                                         |
              /                                        DMS-300
       DMS-Supernode ---------- DMS-100             (int services)
      (maint,billing)            / | \                    |
                           (subscriber lines)             |
                                                          +--- International
                                                               Gateway

       DMS Applications and Markets

Switch    Application                 Class      Market
-------   --------------------------- ---------  -------------------------
DMS-100   End Office                   5         Local Exchange Carriers
DMS-200   Toll Office                  4         Local Exchange Carriers
DMS-
100/200   End Office/Toll Office       5         Local Exchange Carriers
DMS-250   Tandem Toll Center          4,3,2,1    Interchange Carriers
DMS-300   International Gateway      CTI-3,CTX   Int. LD Carriers
DMS-MTX   Mobile Telephone Center                Cellular Servers
Meridian
ACD Srvr  Adjunct ACD Switch                     Local Exchange Carriers


Refrences:  The DMS100 Advantage  (nt)