Nortel DMS-100 Digital Central Office Switch Family
Nortel's DMS (Digital Multiplex System) is the family of digital central-office switches that Northern Telecom introduced at the end of the 1970s and developed through the DMS SuperNode and SuperNode SE generations. Every member shares the same skeleton: a duplicated central control complex, a fully duplicated two-plane time-division network, peripheral modules that terminate subscriber lines, analogue trunks and DS1 carriers, and a maintenance and administration position. That architecture spans the DMS-100 local exchange, the DMS-200 toll switch, the combined DMS-100/200 and the DMS-300 international gateway, with line capacity from 1,500 to more than 100,000 subscribers and remote line modules extending the serving area over DS1 links. Later SuperNode SE offices add computing-module and message-switch shelves running BCS software. YT CIG supplies tested second-hand DMS circuit packs from stock: +5/+12 V converters, combined clock cards and IPF bus interfaces, plus further DMS-100 series packs listed by part number. Send us the PEC and quantity and we will confirm condition and lead time.
Technical specifications
| Platform type | Modular, software-controlled digital multiplex switching system for central-office local and toll service |
|---|---|
| Family variants | DMS-100 (local), DMS-200 (toll), DMS-100/200 (combined local and toll), DMS-300 (international gateway) |
| Local line capacity | 1,500 to more than 100,000 subscriber lines (DMS-100) |
| Trunk capacity | Between 400 and 60,000 trunks, in the mix of trunk types the office serves (DMS-200); up to 25,000 international trunks (DMS-300) |
| Functional areas | Central Control Complex (CCC), Switching Network (NET), Peripheral Modules (PM), maintenance and administration area |
| Central control | Duplicated CPU, program store, data store and central message controller; CPU word length 16 bits plus parity, 111 ns microcycle, 36 MHz clock |
| Switching network | Four stages of time switching per connection; fully duplicated as Plane-0 and Plane-1 |
| Network module | 8×8 time-switch arrangement (8 IC-XPT plus 8 OG-XPT per side); 64 incoming and 64 outgoing ports per side; 2,048 channels per side (1,920 voice + 128 message) |
| Maximum network size | Up to 32 network modules per plane (NM-0 to NM-31); 64 frames for the full network; 61,440 voice channels per direction per plane |
| Speech link format | 32 channels per link (30 voice + 2 message) at 2.56 Mbit/s, 2-way 4-wire |
| Line module capacity | Up to 640 analogue subscriber lines per LM; one bay with four line shelves and one LMC shelf; five line drawers of 32 line cards per shelf |
| Digital carrier module | Up to five DS1 links per DCM (5 x 24 = 120 voice channels), matching four 30-channel speech links |
| Trunk module | Up to 30 analogue trunks per TM, encoded to 8-bit PCM and carried on one 2.56 Mbit/s link |
| System clock | Stability 1 part in 10^-6; 8 kHz framing derived from the same source; two synchronized 10.24 MHz crystal sources, one CMC on standby |
| Power | Nominal -48 V DC battery plant; normal -49 to -53.5 V; extreme -44.75 to -55.8 V |
| Frame and shelf dimensions | Frame 27 x 18 x 84 in (686 x 457 x 2,100 mm); shelf 26 x 12.5 x 14 in (660 x 318 x 356 mm) with 24 in (610 mm) usable between side plates |
| Environmental range | 10-30 °C normal, 5-49 °C extreme; 20-50% RH normal, 20-80% RH extreme (extreme up to 72 hours) |
| Call capacity and reliability | 350,000 call attempts during the busiest hour of an average busy season; less than 2 hours downtime in 40 years |
| Software language | PROTEL (Procedure Oriented Type Enforcing Language), with separately compilable feature modules |
| Later generation | DMS SuperNode SE, BCS36 and up; card replacement documentation Standard 03.02 dated December 1993 |
| Clock card (message switch shelf) | NT9X53 AC, combined clock card; replaced in a message switch shelf with clock mastership switched first |
| CM/SLM power converter | NT9X91 AA, storage device power converter in a computing module/system load module shelf, powered in pairs with NTDX15 |
| Network module card sets | NT0X48, NT5X13 and NT8X11 network module card sets; each network module presents 64 incoming and 64 outgoing ports |
What we supply
- DMS-100 +5/+12 V power converters (NT9X91AC08)
- DMS-100E combined clock / system clock modules (NT9X53AAE1)
- DMS-100 IPF bus interface packs (NTEX22BA17, NTEX22BA11)
- DMS-100 series circuit packs listed by PEC (NT8X14AA, NTCX10AA, NTCX11AA)
Sourcing on request
- NT9X91 storage device power converter variants (suffixes other than AA)
- NTDX15 computing module / system load module power converter
- Message switch shelf cards: NT9X49, NT9X52, NT9X54, NT9X62, NT9X69, NT9X73, NT9X79
- Computing module / system load module cards: NT9X62, NT9X86, NTDX15
- Network module card sets: NT0X48, NT5X13, NT8X11
Units in our inventory
8 NORTEL variants in the DMS family, 7 of them with published specifications shown side by side below. Ask us for live stock, condition and lead time on any line item.
| Part number | Voltage V |
|---|---|
| NT8X14AA | — |
| NT9X53AAE1 | — |
| NT9X53AD21 | — |
| NT9X91AC08 | 48V DC |
| NTCX11AA | — |
| NTEX22BA11 | — |
| NTEX22BA17 | — |
Variants in this family
- NT8X14AA — The NT8X14AA is an original Nortel Networks spare part designated for the DMS 100 Series platform. As part of the "Other" category, this component does not…
- NT9X53AAE1 — The NT9X53AAE1 is a used Nortel Networks DMS-100E SYS Clock Module. In the DMS-100E switching platform, a system clock module typically provides timing reference and synchronization…
- NT9X53AD21 — The Nortel Networks NT9X53AD21 supplies clock references to DMS-BUS system architecture, keeping switching fabric timing aligned across the central office shelf.
- NT9X91AC08 — The Nortel Networks NT9X91AC08 is a converter power supply module engineered for the DMS-100 central office switching system. As a +5/+12 CONVR unit, it steps a…
- NTCX10AA — A Nortel Networks DMS 100 series component, this unit performs its assigned role within the switching system's established architecture.
- NTCX11AA — The NTCX11AA is a Nortel Networks component identified with the DMS 100 Series. It is classified as a Class 5 local office digital multiplex system switch,…
- NTEX22BA11 — The Nortel DMS-100 IPF bus interface board links input/output frame resources to the switch, maintaining the bus paths DMS-100 operation requires.
- NTEX22BA17 — The Nortel Networks NTEX22BA17 is a DMS-100 IPF bus interface card. The IPF bus connects IP-function resources within the DMS-100 switching architecture, and interface cards of…
Every NORTEL item above is quoted to order: tell us the part number, quantity and destination and we reply with availability, condition and price. Request a quote