Centigram Communications Achieves Interoperability Approval for the Series 6 Platform and C-SMSC at the Nortel Networks MTX Open Solutions Lab.

SAN JOSE, Calif.--(BUSINESS WIRE)--Nov. 15, 1999--

Centigram Communications Corporation, (Nasdaq:CGRM) and Nortel Networks (NYSE/TSE:NT) today announced the successful completion of interoperability testing of the Centigram Short Message Service Center (C-SMSC) and the Centigram Series 6 enhanced services platform at the Nortel Networks MTX Open Solutions Lab in Richardson, Texas.

The Series 6 platform and C-SMSC -- a software module that integrates with the Series 6 -- were put through a rigorous testing regimen and found to be fully interoperable with the MTX08 switch generic on Nortel Networks DMS-MTX switching system. The Centigram Series 6 received approval for both CDMA and TDMA SMS environments.

C-SMSC is the first offering in a comprehensive series of unified communications products from Centigram that is ushering in a new era of personalized communications. C-SMSC enables the transmission of alphanumeric messages between mobile telephone subscribers and any short message-generating systems such as the Internet or a corporate LAN.

Telecommunications carriers can deploy C-SMSC to provide mobile customers with access to email or Internet-based text content such as stock updates, news, traffic reports and weather information.

"Interoperability with the Nortel Networks' DMS-MTX digital mobile switching system opens up a wide range of new opportunities for Centigram," said Janine Roth, Centigram's Vice President of Marketing and Corporate Business Development.

"By leveraging our expertise with voice messaging, call processing and Internet-enabled text-based messaging, Centigram is creating advanced systems that unify voice and data to create valuable new communications products.

"Mobile carriers, network service providers and Internet content providers can all use these unified communications systems to open new markets and deliver cutting-edge services. This approval from Nortel clears the way for Centigram to deploy next-generation C-SMSC-based services over one of the industry's predominant mobile switching systems."

Centigram's Series 6 Platform enables wireless and wireline telecommunications service providers to deploy advanced communications services. Based on a scalable, standards-based modular expandable system architecture (MESA), the Series 6 system enables carriers to seamlessly add new capacity and additional features, without having to change existing equipment.

The Series 6 system supports a comprehensive range of capabilities, including Internet-enabled multimedia messaging, mailbox-on-demand services, and C-SMSC, a software-only solution that enables carriers to cost-effectively deliver SMS-based mobile data services.

With SS7 connectivity and OMAP functionality, the Series 6 platform is compatible with all major wireless networks and standards deployed worldwide, including North America, Europe, Asia and Latin America.

The Nortel Networks Open Solutions Program is designed to give vendors the information, tools and support they need to expand their own business, while helping wireless operators to quickly deploy Wireless Intelligent Network solutions.

Open Solutions is an open interface, integration, and support program that encourages external vendors to connect their service platforms to the Nortel Networks DMS-MTX system.

Nortel Networks' commitment to an open architecture for off-board applications gives third-party vendors such as Centigram the opportunity to test their products on Nortel Networks' equipment prior to integrating these solutions into an operator's network.

The testing facility provides a simulated network environment for testing and fine-tuning new applications before they are deployed commercially -- helping Nortel Networks, its customers, and enhanced services providers like Centigram to deliver reliable and innovative subscriber services and solutions.

Nortel Networks

Nortel Networks is a global leader in telephony, data, wireless and wireline solutions for the Internet. The Company had 1998 revenues of (US)$17.6 billion and serves carrier, service provider and enterprise customers globally. Today, Nortel Networks is creating a high-performance Internet that is more reliable and faster than ever before.

It is redefining the economics and quality of networking and the Internet through Unified Networks that promise a new era of collaboration, communications and commerce. Visit us at www.nortelnetworks.com

Centigram Communications Corporation

Centigram Communications Corporation (Nasdaq:CGRM) is a leading global provider of Internet-enabled call management and unified communications services to mobile and landline telecom service providers.

Leveraging its expertise in voice messaging, call processing and IP-enabled multimedia messaging, the company is delivering next-generation communications services that enable the transmission of voice, text, and multimedia content to wireless and wireline phones, PCs and other devices.

Centigram is headquartered at 91 East Tasman Drive, San Jose, CA, 95134. Phone [phone], fax [phone], or Web http://www.centigram.com. Centigram has sales and support offices in North America, Europe, Asia, Latin America, and Australia.

Note to Editors: Centigram is a registered trademark of Centigram Communications Corporation. All other trademarks and registered trademarks are the property of their respective owners. There is also an asterisk after Unified Networks.