Larscom's V.35 Port for Access-T45 DS3 Network Service Unit Allows Customers to Integrate Legacy Equipment Into Broadband Networks.

SANTA CLARA, Calif.--(BUSINESS WIRE)--April 30, 1997--Larscom Incorporated (NASDAQ: LARS) today introduced a V.35/RS449 high-speed serial port option for its Access-T45 DS3 Network Service Unit.

It allows service providers and enterprise users to integrate legacy equipment such as low-end routers and switches into their networks. Using the Access-T45 with its new data port, customers can ramp up their networks' data rates without incurring the cost of an equipment upgrade, and without having to purchase an expensive HSSI port. In particular, this solution is ideal for remote locations requiring a hub-and-spoke architecture using Larscom's Orion 4000 broadband access multiplexer with its recently announced T3Clear modules as the hub.

"With the Internet creating skyrocketing bandwidth requirements, the ability to be able to upgrade to higher-speed connections such as T3 and fractional T3 has become critical," noted Curtis Price, Research Manager, IDC. "Larscom's enhancement to its Access-T45 will allow users to easily integrate key legacy equipment into their broadband networks, and therefore protect the investment in their existing infrastructure. I believe this additional port option will especially appeal to the Internet Service Providers who are busily ramping up data rates throughout their networks."

Larscom's Access-T45 allows one or two high-speed devices such as routers, video codecs, switches, and front-end processors to access the 45 Mbps bandwidth of a DS3 (T3) connection in increments of 3.2 Mbps. The new V.35/RS449 data port increases the customer's broadband options in a couple of attractive ways. The Access-T45 can be connected to a high-speed device via V.35/RS449 to access fractional T3 bandwidth up to 12.6 Mbps, and have an easy migration path to higher bandwidths (up to 44.2 Mbps) by switching to a HSSI connection. Or, if the user is already employing a HSSI connection at less than 44.2 Mbps, the unused portion of the DS3 bandwidth can be allocated to a lower-speed device by employing a V.35/RS449 interface.

"This enhancement to Access-T45 is an important part of our continuing commitment to broadband access solutions," said Peter Prichard, Director of Broadband Product Management for Larscom. "While HSSI ports are a standard solution for high-speed devices at or near DS3 bandwidth (45 Mbps), our customers have told us they also need a cost effective solution for using Access-T45 with V.35/RS449 devices for data rates to around 12 Mbps."

Access-T45 features advanced performance monitoring and diagnostics with built-in bit error rate test capability, thus eliminating the need for expensive test equipment. Multiple management options include an integral SNMP agent. Access-T45 is priced at $6,950 for either the HSSI/V.35 or the dual HSSI version. To obtain additional product information, please visit the company's web site at www.larscom.com . To arrange an interview, contact Michelle Solis at [phone] ext 274. For investor relations issues, contact Morgen-Walke Associates at [phone].

Larscom Incorporated (NASDAQ: LARS) is a leading provider of high speed wide area network (WAN) access equipment. Its customers include carriers, Internet service providers, corporate users, and government agencies worldwide. Its products cover a wide range of transmission rates and services including full and fractional T1, E1, NxT1, NxE1, and T3, as well as frame relay and ATM inverse multiplexing. To help ensure optimum network performance, Larscom products feature advanced monitoring, diagnostic, and management functions, including SNMP. The company's headquarters are located at 4600 Patrick Henry Drive, Santa Clara, California 95054.

Any forward looking statements in this news release are based on current expectations and beliefs and are subject to risks and uncertainties that could cause the actual results to differ materially. Factors that could cause actual results to differ materially include customer concentration, dependence on recently introduced products and products under development, rapid technological change, no recent independent operating history, fluctuations in quarterly operating results; absence of significant backlog, as well as additional risk factors as discussed in the "Risk Factors" section of Larscom's prospectus, dated December 18, 1996, and Larscom's quarterly reports filed with the U.S. Securities Exchange Commission (SEC).

CONTACT: Larscom

Ursula Burger, 408/988-6600