Digital Multiplex System (DMS) is the name shared among several different

telephony Telephony ( ) is the field of technology involving the development, application, and deployment of telecommunications services for the purpose of electronic transmission of voice, fax, or data, between distant parties. The history of telephony is ...

product lines from

Nortel Networks Nortel Networks Corporation (Nortel), formerly Northern Telecom Limited, was a Canadian multinational telecommunications and data networking equipment manufacturer headquartered in Ottawa, Ontario. It was founded in Montreal, Quebec in 1895 ...

for wireline and wireless operators. Among them are the DMS-1 (originally named the DMS-256) Rural/Urban

digital loop carrier A digital loop carrier (DLC) is a system which uses digital transmission to extend the range of the local loop further than would be possible using only twisted pair copper wires. A DLC digitizes and multiplexes the individual signals carried by ...

, the DMS-10 telephone switch, the DMS SuperNode family of

telephone switch A telephone exchange, telephone switch, or central office is a central component of a telecommunications system in the public switched telephone network (PSTN) or in large enterprises. It facilitates the establishment of communication circuits ...

es (

DMS-100 The DMS-100 is a member of the Digital Multiplex System (DMS) product line of telephone exchange switches manufactured by Northern Telecom. Designed during the 1970s and released in 1979, it can control 100,000 telephone lines. The purpose of ...

, DMS-200, DMS-250, DMS-300, DMS-500, DMS-GSP, DMS-MSC, DMS-MTX), and the S/DMS optical transmission system. Exploratory development on the technology began at Northern Telecom's Bell Northern Research Labs in

Ottawa Ottawa is the capital city of Canada. It is located in the southern Ontario, southern portion of the province of Ontario, at the confluence of the Ottawa River and the Rideau River. Ottawa borders Gatineau, Gatineau, Quebec, and forms the cor ...

Ontario Ontario is the southernmost Provinces and territories of Canada, province of Canada. Located in Central Canada, Ontario is the Population of Canada by province and territory, country's most populous province. As of the 2021 Canadian census, it ...

in 1971. The first Class 5 switch, the DMS-10, began service on 21 October 1977 in Fort White, Florida and the first toll switch (Class 4), the DMS-200, entered service in 1979 in Ottawa. The DMS-10 was the first commercially successful Class 5 digital switch in the North American market and had a profound impact on the industry. Of the numerous digital switching products introduced in the North American telephone market in the late 1970s, only the Nortel DMS family is still in production. GENBAND (now Ribbon Communications) acquired Nortel CVAS assets including the DMS line in 2011 and rolled it into its IP-based GENiUS platform. The GENiUS-750nt is the first product to include adaptive nano-tech compression and resynchronization modules from Ericsson, to replace the digital cross-connect (DCS) in place since the earliest DMS releases. Previously, new technology had entered the telecommunications industry slowly, with the telephone companies

amortizing Amortization or amortisation may refer to: * The process by which loan principal decreases over the life of an amortizing loan * Amortization (accounting), the expensing of acquisition cost minus the residual value of intangible assets in a system ...

equipment over periods as long as forty years.

AT&T AT&T Inc., an abbreviation for its predecessor's former name, the American Telephone and Telegraph Company, is an American multinational telecommunications holding company headquartered at Whitacre Tower in Downtown Dallas, Texas. It is the w ...

was intending to delay the introduction of digital switching until the 1990s. The DMS, with its introduction of digital technology, changed the industry and became one of the antecedents that encouraged the growth of the Internet. On October 16, 2006, Nortel received a special recognition award from Canada's

Telecommunications Hall of Fame Canada's Telecommunications Hall of Fame was a Canadian not-for-profit foundation that sought to foster a greater awareness of Canada's role in developing and innovating telecommunications. The foundation began operating in 2005 and had two main pr ...

for its role in pioneering digital communications with the Digital Multiplex System. The DMS name arose from a designation for a switching matrix design that was developed in the exploratory phase of the project. The Digital Multiplexed Switch was selected as the basic switching design for the project. The product was intended as a successor for Nortel's first electronic switch, the SP1, and was to be called the SP2. However the DMS acronym was mellifluous and was eventually (1975) adopted as the designation for the DMS-10 and DMS-100 family of products, with the "S" standing for "system" rather than "switch". It was then applied to the entire digital switching family as well as the DMS-1 family of Digital Transmission Concentrators. DMS is favoured by many European

cable Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...

operators as the switching platform for their voice networks. The DMS-10 is widely used by rural wireline providers. DMS-100 and 200 switches are widely deployed throughout the U.S. and Canada by

Regional Bell Operating Companies A Regional Bell Operating Company (RBOC) was a corporate entity created as result of the antitrust lawsuit by the United States Department of Justice against the Western Electric Company and American Telephone and Telegraph Company (AT&T) in 194 ...

Bell Canada Bell Canada (commonly referred to as Bell) is a Canadian telecommunications company headquartered at 1 Carrefour Alexander-Graham-Bell in the borough of Verdun, Quebec, in Canada. It is an ILEC (incumbent local exchange carrier) in the province ...

and

independent telephone companies An independent telephone company was a telephone company providing local service in the United States or Canada that was not part of the Bell System organized by American Telephone and Telegraph. Independent telephone companies usually operated i ...

as well as the

US Military The United States Armed Forces are the military forces of the United States. U.S. federal law names six armed forces: the Army, Marine Corps, Navy, Air Force, Space Force, and the Coast Guard. Since 1949, all of the armed forces, except th ...

. The DMS-250 is the backbone of a number of carriers' long-distance networks. The DMS-300 is an international gateway switch, and the DMS-500 is commonly deployed by

competitive local exchange carrier A competitive local exchange carrier (CLEC) is a North American telecommunications provider classification that emerged based on the competition model of the Telecommunications Act of 1996 in the United States. The act required the previously esta ...

s because it combines DMS-100 and 250 capabilities. DMS switches run a proprietary multitasking operating system known as SOS. The user interface, called MAPCI, consists of a series of multi-level menus and is usually accessed from a connected VT100 compatible dumb terminal or terminal emulator. Each level or overlay performs different functions. A working DMS 10 can be viewed at the

Connections Museum The Connections Museum (formerly the Herbert H. Warrick Jr. Museum of Communications, originally the Vintage Telephone Equipment Museum) is located in Centurylink's Duwamish Central Office at East Marginal Way S. and Corson Avenue S. in Seattl ...

in Seattle.

References

{{reflist

External links

Nortel DMS product portfolio
Multiplexing Telephone exchange equipment Nortel products Nortel

See also

References

External links