Vendor Network Architectures�Part III: Nortel

Alexander Graham Bell, a Scotsman by birth, emigrated with his family to Brantford, Ontario, Canada in 1870. Bell subsequently moved to Boston and taught speech to the hearing impaired. During a return to Canada in the summer of 1874, Bell conceived the idea of the telephone, and was granted a U.S. patent for that work in 1876. The patent rights were assigned to the National Bell Telephone Company (U.S.) and the Bell Telephone Company of Canada. To maintain these patent rights, Bell Telephone of Canada started its own telephone manufacturing company in 1882, named the Mechanical Department, which incorporated as the Northern Electric and Manufacturing Company in 1895. In 1899, Bell Canada added a cable and wire manufacturing company to their portfolio, which was formally merged with the manufacturing company in 1914, under the name of the Northern Electric Company, and jointly owned by Bell Canada and the U.S. firm Western Electric. In 1949, the U.S. Justice Department required AT&T to split off its Western Electric and Bell Laboratories subsidiaries, and as a result, the Western Electric stock holdings in Northern Electric were sold to Bell Canada.

Northern continued their research into telephony, and added electromechanical switching systems, television, microwave, and video switching to their areas of expertise. Research into digital speech processing followed, with the company releasing the Digital Multiplex Switch (DMS) system for central office switching, and the SL-1, a fully digital PBX, in the early 1970s. By the early 1980s, Northern Telecom had established manufacturing facilities in the United States, and expanded as a worldwide supplier of both central office and enterprise switching systems. In 1995, and in celebration of the one-hundredth anniversary of the founding of Northern Electric, the company’s name was changed to Nortel.

Given their strong history in both central office and premises switching systems, it should come as no surprise that Nortel targets their switching products to both the enterprise and carrier markets. Their overall architecture is called ACE—the Architecture for the Converged Enterprise—and it consists of three key products: the Business Communications Manager (BCM), the Communications Server (CS) 1000 and 2000, and the Multimedia Communications Server (MCS) 5100 and 5200.

The Business Communications Manager is an IP-enabled, single-platform communications system for small and medium sized businesses and branch offices. It primarily addresses the enterprise market, but can also serve as a small site solution for hosted services. The BCM scales from 10 to over 200 digital or IP-based stations, and includes a large suite of applications, including routing, fax, voice messaging, interactive voice response, multimedia call center, and wireless capabilities within a single system.

The Communication Server 1000 is a server-based IP-PBX, which combines the benefits of a converged network and IP applications with over 450 telephony features. The CS 1000 addresses the enterprise markets from either a private, customer-managed solution, or as part of a managed service solution from a service provider. It can handle up to 15,000 IP clients per call server, with support for ISDN, H.323 and SIP signaling.

On the carrier side, the Communication Server 2000 softswitch is a single platform for very large enterprises. It is designed as the basis of a multi-customer hosted solution, or as a foundation for IP-centrex services. It provides local, long distance and tandem call services, and functions as the intelligent core of a multiservice network. Each CS 2000 can handle up to 250,000 lines, with support for H.248, H.323, MGCP and SIP protocols.

The Multimedia Communications Servers deliver SIP-based multimedia and collaborative communications applications to augment existing voice and data capabilities. The applications provided include video calling and conferencing, picture caller ID, white boarding and file exchange, co-web browsing, instant messaging, plus personal call management features. The MCS 5100 is an enterprise version, supporting up to 60,000 active subscribers, while the MCS 5200 is a service provider version for hosted services, with support for 100,000 subscribers.

Further details on the Nortel architecture and products can be found at Our next tutorial will continue our examination of vendors’ softswitch architectures.

Copyright Acknowledgement: © 2005 DigiNet ® Corporation, All Rights Reserved

Author’s Biography
Mark A. Miller, P.E. is President of DigiNet ® Corporation, a Denver-based consulting engineering firm. He is the author of many books on networking technologies, including Voice over IP Technologies, and Internet Technologies Handbook, both published by John Wiley & Sons.

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