GenBand / Nortel DMS-100 Magnetic Tape Emulation


Nortel was a Canadian telecommunications company, with a staff at its peak of almost 100,000 worldwide. It sought protection from creditors in 2009 and has now ceased trading. Founded in 1895 Nortel was a pioneer in many aspects of telecommunications including electromechanical switches, satellite communications, X.25 data and digital switch equipment. The DMS-100 was introduced in 1979.

Installed Base

DMS-100 systems have been widely deployed in the U.S. and Canada.

DMS-100 relies on magnetic tape drives for AMA/billing data and also for office data backup and exchange restart. With product introduction in 1979 these devices are now up to 35 years old, and while the solid-state switches are still running, DMS-100 Magnetic Tape Emulation is becoming necessary as tapes and parts are expensive and hard to obtain.


The DMS-100 systems typically use a Cook 2216 1600bpi PE (Phase-Encoded) interface with both formatted and unformatted options.

The formatted and unformatted interfaces operate at quite different levels, the formatter being a separate part which makes interfacing with the unit easier.

The DDS XM-100 can emulate both of these interfaces (formatted and unformatted) without requiring an adapter or additional cabling: all signals are interpreted and generated within the DDS.


DDS supports the standard -48V power via a 6-pin connector, but can also work with 12V in cases where that is more convenient.

Connectors on the rear of the DDS provide a physical connection to the DMS-100, typically via an IDC cable. If existing cabling is not suitable this can be supplied. The exchange does not need to be power cycled for installation.


The DDS XM-100 is a drop-in replacement for the DMS-100 tape drive, uses the same commands from the exchange, and performance backups and restores in the same way.

Generic DDS documentation and training (dealing with virtual tapes, exchange restarts, network operation) is provided. Technicians can be readily trained to perform installation in remote sites, and deal with ongoing maintenance issues that arise.


DDS is supplied with a 24 month warranty which can be extended up to 6 years if required. On-site support is typically provided via installation / support partners in-market.