Alcatel Telecom demonstrates complete SONET-SDH-ATM interoperability for international networks.

RICHARDSON, Texas--(BUSINESS WIRE)--May 30, 1996--At its interoperability testing center located on the campus of Alcatel Network Systems here, Alcatel Telecom has demonstrated SONET (synchronous optical network) OC-3c (155 Mbit/s) and SDH (synchronous digital hierarchy) STM-1 (155 Mbit/s) traffic payload compatibility over its complete line of multiplexer and cross connect products. Alcatel thus becomes the first company to demonstrate clear, seamless payload exchange compatibility at a data rate that links U.S.- and European-standard payloads.

This achievement assists carriers in three important ways. First, it unlocks the potential for international broadband networks based on pure, highly reliable optical end-to-end connections. This allows the industry to move away from bandwidth-limited and less reliable copper coaxial cable connections to establish broadband inter- and intra-office facilities. Second, Alcatel has demonstrated how carriers can deploy seamless SDH/SONET networks that require less equipment -- thus promoting reliability and survivability across borders and oceans. Third, this achievement promotes the establishment of international and domestic ATM (asynchronous transfer mode) services over public backbone networks at the industry-favored OC-3c and STM-1 rates.

"Our customers are demanding OC-3c and STM-1 rates and we are removing the roadblocks to achieving this type of international service," said Tom McDermott, vice president and chief technical officer for Alcatel Network Systems. "We have proven this interoperability with all three payload formats: STM-1, STS-3c and STS-1."

Alcatel conducted payload testing over a SONET ring run by an Alcatel 1648 SM SONET multiplexer. The 1648 SM delivered the SDH payloads as it would SONET payloads because it reads both SONET and SDH "overhead" routing and content information. Another test proved Alcatel compatibility with traffic handoff between a SONET ring and the Alcatel 1641 SX SDH standard digital cross connect. Lastly, in cooperation with customers, Alcatel verified "transparent" SONET-to-SDH gateway functionality with non-Alcatel SDH equipment.

Alcatel Telecom activities in North America include the design, manufacture and service of a full line of voice, data, video and multimedia telecommunications products -- such as ATM switching systems, digital cross connects, fiber optic transmission systems, optical amplifiers, microwave radios, wireless communications switches, video codecs, and network management systems. The telecommunications and broadcast industries, private operators and corporations use these products to create high performance networks. The worldwide operations of Alcatel Telecom makes it one of the world's leading communications equipment manufacturers. Alcatel Telecom is part of the Alcatel Alsthom group, which maintains its headquarters in Paris. Alcatel Alsthom trades on the NYSE as ALA.

CONTACT: Alcatel, Richardson

Michael Newsom, 214/996-7896

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