Trillium Digital Systems Inc. announces V5.2 source code software product.

LOS ANGELES--(BUSINESS WIRE)--April 14, 1997--Trillium Digital Systems Inc. announced the release of its source code software products supporting the European Telecommunications Standards Institute (ETSI) specification for the digital local exchange V5.2 signalling and switching protocol.

This latest release adds the System Manager, Bearer Channel Connection (BCC), Link Control and Protection protocols and completes Trillium's V5.2 protocol stack.

Trillium initially released its V5.1 protocol stack in July 1996. It completed the V5.2 protocol stack in February to meet the growing demand for Digital Loop Carrier (DLC) and Wireless Local Loop (WLL) software technology.

Trillium Chief Technical Officer Larisa Chistyakov said: "The demand for V5.2 capabilities in the Access Network (AN) and Local Exchange (LE) market has accelerated dramatically over the last three to six months. DLCs are increasingly demanding these capabilities, especially for growing cable systems in Europe and North America.

"In Asia, particularly China, and emerging markets such as Latin America, the Wireless Local Loop is fast becoming a solution for countries struggling to improve physical telecommunications infrastructures.

"Analysts estimate more than 80 percent of the world's people do not own a telephone and close to 50 percent have never used one. This need creates new opportunity for telecommunications equipment manufacturers. Trillium's release of the complete V5.2 protocol stack is a continuation of our efforts to help these manufacturers quickly deploy V5 software technology and use it to manage bandwidth bottlenecks efficiently."

The V5.2 protocol is based on a dynamic concentrator principle and builds on the earlier V5.1 protocol, which is based on the principle of a static multiplexer. V5.2 uses a digital common-channel signalling protocol to establish, maintain and release calls between an AN and LE. These calls are carried over 64 kilobit/sec time slots supported by an underlying trunk interface.

The V5.2 protocol enables the interconnection of multiple access types, including ISDN and analog circuits, over the same trunk interfaces which are being used for large-scale WLL and DLC systems.

The main differences between the V5.1 and V5.2 protocols are:

-- V5.2 allows multiple (up to 16) E1 (30 channels) links per interface whereas V5.1 allows for only one E1 link per interface.

-- V5.2 allows dynamic allocation of time slots to ISDN and PSTN user ports with the help of the BCC Protocol. V5.1 has static connections, or one-to-one, ports and time slots.

-- V5.2 verifies link states and identities, blocks and unblocks them and provides a coordinated switchover to back-up links during failures or required maintenance of the primary signalling link.

Chistyakov said: "Trillium offers an open software solution and has extensive experience in ensuring interoperability between vendors and systems used in the telecommunications infrastructure. We are confident in our ability to solve V5.2 interoperability problems between the Access Network and Local Exchange, especially with our history in ATM, SS7, Frame Relay and ISDN.

"We developed the V5.1 and V5.2 protocols in response to strong demand from customers that require these signalling protocol capabilities. Our complete V5.2 Access Network stack compiles to about 200k bytes of object code in a typical environment. We have shipped these products to a number of customers that are already working with the code."

Trillium's V5.2 protocol stack includes all V5.1 protocols along with additional V5.2 features. The V5.2 protocol stack supports both the AN and the LE.

The V5.1 protocol stack features provide the following:

-- The Control Protocol manages the blocking and unblocking of user ports for both ISDN and analog circuits between the AN and the LE.

-- The Public Switched Telephone Network (PSTN) protocol supports connection establishment, clearing, and re-start and port blocking procedures. It also supports procedures to exchange PSTN line conditions and to identify ports and connections for layer 3 addresses.

-- The Link Access Protocol for V5 (LAPV) protocol provides the data link protocol needed to reliably send and receive data between the AN and LE.

-- The Enveloping Function Protocol enables multiplexing and demultiplexing of ISDN D-channel information from the V5 interface using envelope function addresses.

Additional V5.2 protocol stack features provide the following:

-- The System Manager provides the capabilities to manage and coordinate activities of V5 protocols and resources. It supports coordinated start-up sequences, handles port and common control functionality, and coordinates link control and C-channel switchover through different V5 protocols.

-- The Bearer Connection Channel protocol supports dynamic allocation from bearer channels to user ports for both single and multislot connections. It also audits bearer channels.

-- The Link Control protocol supports link identification verification and link blocking and unblocking procedures.

-- The Protection Protocol supports procedures required to perform coordinated protection switchover to the back-up communication channel in case of failure or required maintenance of the primary one.

Trillium deliverables include source software, documentation, a training course and technical support.

Trillium Digital Systems, a privately held company founded in 1988, develops, markets, licenses and supports standards-based portable and integrated communications software. Trillium offers software for the Signalling System 7 (SS7), Asynchronous Transfer Mode (ATM), Integrated Services Digital Networks (ISDN), Frame Relay, V5, Internet Protocol (IP) and X.25 communications protocols.

Trillium is a leading supplier of communications software technology to computer and communications equipment manufacturers. It has licensed its source software to more than 200 companies worldwide for use in a wide range of switching, network access, service platform, operating system and test equipment products.

Trillium communications software is written in the C programming language and is designed to be licensed in source form by manufacturers for integration into computer and communications products. Manufacturers license Trillium's software technology to significantly speed time-to-market, reduce the risk and lower the cost of developing and providing standards-based communications protocols within their products. -0- NOTE: Trillium and Trillium Digital Systems are registered trademarks of Trillium Digital Systems Inc. Other referenced trademarks are trademarks (registered or otherwise) of the respective trademark owners.

CONTACT: Trillium Digital Systems Inc.

Kim Billingsley, 310/442-9222

310/442-1162 (fax)

Web: http://www.trillium.com