TranSwitch Envoy-XE Provides Optimal Alternative to LAN-Class Switches and NPUs.

SHELTON, Conn. -- Layer 2/2.5 Packet Processor is Industry's First Carrier Class Integrated MAC/switch/traffic Manager with OIF SPI Interface

TranSwitch(R) Corporation (NASDAQ: TXCC), a leading provider of high-speed Broadband, Switching, and Transport semiconductor solutions for voice, data and video communications, today announced the Envoy(TM)-XE, a single-chip Ethernet/VLAN/MPLS switch and traffic manager for Ethernet in the first mile (EFM) and access applications. Envoy-XE can be used for offload or replacement of traditional NPU functions like QoS at Layer 2 (VLAN, MPLS) and Layer 3 (IP ToS), and VLAN service statistics. The new device is an excellent fit in access and edge switches and routers, MSPPs/MSTPs (multiservice provisioning platforms/multiservice transport platforms), IP-DSLAMs, and BTSs (base transceiver stations).

The Envoy-XE brings TranSwitch's Envoy product family of carrier-class Ethernet controllers to a higher level of performance and functionality. It adds the ability to perform wire-speed Ethernet, VLAN, and MPLS switching for 75 ports together with traffic management including MEF- and IETF-compliant dual leaky bucket policer and advanced scheduling in a single chip. Like Envoy-CE2/-CE4, it aggregates Fast Ethernet (FE) and Gigabit Ethernet (GE) ports to a SPI-3 interface, but Envoy-XE's switch and traffic management blocks enable aggregation to one or more Ethernet ports as well.

"Envoy-XE is the first device in the MAN/WAN ASIC market to offer the complete carrier-class feature set demanded by OEMs," said Brian Stroehlein, product marketing manager for TranSwitch. "This is not just a LAN chip repackaged and repurposed for carrier equipment use. Our device's OIF SPI-3 interface (Optical Interface Forum System Packet Interface, Level 3) allows for glueless connection to popular NPUs and SONET/SDH framer/mapper devices, thus shortening development time and lowering costs. Envoy-XE's standards-compliant marking and WRED (weighted random early discard) mechanism help relieve congestion should it start to occur, enabling carriers to provide different service levels for different types of traffic. During periods of congestion, Envoy-XE preserves high priority traffic over lower priority traffic."

Envoy-XE offers two rate three color marker (trTCM) policing per MEF Tech Spec 10 and IETF RFC 2698. Using trTCM, ingress service frames are marked for dropping according to a predefined bandwidth profile consisting of a committed information rate (CIR) and peak information rate (PIR). Frames in flows below the CIR are marked green; frames in flows above the CIR but below the PIR are marked yellow; and frames in flows above the PIR are marked red. Red frames are always dropped, and yellow frames may be forwarded based on queue availability. Other carrier-class features include super jumbo frame support for FE and GE; per-port flow control with no head-of-line blocking on the SPI-3 interface; a large priority queue buffer based on external DDR SDRAM with optional parity; and IEEE 802.3ah (EFM) PHY-MAC (media access control) backpressure and OAM loopback.

Envoy-XE includes a forwarding engine, internal 8,192-entry MAC table, flexible ingress/egress tag/label processing, MEF-/IETF-compliant traffic manager supporting four classes of service, 2,048 flows, and 256 kbps granularity; support for 4,096 multicast sessions; and per-flow green/yellow/red byte and packet counters for SLA performance monitoring and billing. The device supports all Ethernet Layer 2 formats including untagged frames, VLAN tagged frames, MPLS, Martini, Q-in-Q, MAC-in-MAC and any other future standard Layer 2 frame header format or proprietary header. Envoy-XE features three configurable MACs (cMACs), each of which may be independently configured as eight FE interfaces or one GE interface, two additional dedicated GE interfaces, and a 48-port SPI-3 interface. The packet interface can be optionally configured as a Multi-service Packet Interface (MPI), which offers a Tx-side Payload Length Indicator (PLI) bus, eliminating the need for an extra buffer stage and minimizing latency. MPI is a glueless interface to TranSwitch's EtherPHAST(TM)-48 Plus OC-48/STM-16 Framer/Mapper for Ethernet and SAN.

Envoy-XE comes bundled with TranSwitch's low-level HAL (hardware abstraction layer) and high-level service-oriented APIs, which are license-free and royalty-free. The NPF (Network Processing Forum) compliant API allows for easy integration with commercially available Ethernet and MPLS stacks for standard control and management plane functions.

Customers can obtain samples of Envoy-XE (TXC-06920) in Q3 of 2005. The device is packaged in a 772-pin Plastic Ball Grid Array (PBGA). Pricing is available upon request.

About TranSwitch

TranSwitch Corporation designs, develops and markets innovative semiconductors that provide core functionality and complete solutions for voice, data and video communications network equipment. As a leading supplier to telecom, datacom, cable television and wireless markets, TranSwitch customers include the major OEMs that serve the worldwide public network, the Internet, and corporate Wide Area Networks (WANs). TranSwitch devices for Broadband, Transport and Switching are inherently flexible, many incorporating embedded programmable microcontrollers to rapidly meet customers' new requirements or evolving network standards by modifying a function via software instruction. TranSwitch implements global communications standards in its VLSI solutions and is committed to providing high-quality products and services. TranSwitch, Shelton, CT, is an ISO 9001:2000 registered company. For more information, visit www.transwitch.com.

Forward-looking statements in this release, including statements regarding management's expectations for future financial results and the markets for TranSwitch's products, are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Investors are cautioned that these forward-looking statements regarding TranSwitch, its operations and its financial results involve risks and uncertainties, including without limitation risks of downturns in economic conditions generally and in the telecommunications and data communications markets and the semiconductor industry specifically; risks in product development and market acceptance of and demand for TranSwitch's products and products developed by TranSwitch's customers; risks relating to TranSwitch's indebtedness; risks of failing to attract and retain key managerial and technical personnel; risks associated with foreign sales and high customer concentration; risks associated with competition and competitive pricing pressures; risks associated with investing in new businesses; risks of dependence on third-party VLSI fabrication facilities; risks related to intellectual property rights and litigation; risks in technology development and commercialization; and other risks detailed in TranSwitch's filings with the Securities and Exchange Commission.

TranSwitch is a registered trademark of TranSwitch Corporation. Envoy and EtherPHAST are trademarks of TranSwitch Corporation.