TranSwitch® Corporation and RAD Data Communications Ltd. Announce First VLSI Device in New TDMoIP® Family

October 9, 2003 -TranSwitch Corporation (NASDAQ: TXCC), a leading developer and global supplier of innovative, high speed VLSI semiconductor solutions, and RAD Data Communications today announced the PacketTrunk-4, the first TDM over IP (TDMoIP) device developed as a result of the strategic technology partnership and OEM agreement between the two companies announced earlier this year http://www.transwitch.com/news/article/index.jsp?news=205&category=9. PacketTrunk-4 ushers in a new family of VLSI products that can be used to develop TDMoIP-capable network equipment. These advanced devices enable transparent transport of legacy TDM and serial data over IP/MPLS networks.

PacketTrunk-4 is an internetworking gateway device that efficiently transports TDM trunks over packet-switched networks (PSNs) using TDMoIP, the world's most popular protocol for circuit emulation over IP/MPLS. This single-chip solution incorporates robust clock recovery, encapsulation, jitter compensation, Layer 2/3/4 QoS support, and standards-based support for transport of structured and unstructured TDM signals over a PSN. The device serves as a building block for TDM over IP, TDM over MPLS, or TDM over switched Ethernet networks. Typical applications include:

• TDM services for metro Ethernet, HFC, and broadband wireless carriers

• 2G/2.5G cellular backhaul over IP/MPLS

• HDLC-based data trunking (e.g. Frame Relay) over IP/MPLS

• PSTN-to-IP/MPLS network bridging

• TDM PBX migration to IP/MPLS

• Enterprise private line/toll bypass via Ethernet MAN

• SS7 transport over IP/MPLS

PacketTrunk-4 provides a scalable solution in single-chip to multi-chip configurations. It is a highly integrated VLSI device designed to meet a wide variety of network access and edge requirements. In combination with other TranSwitch products such as QT1F+, QE1F+, T1Fx8, and E1Fx8 framers, the TEPro™ channelized T1/E1/T3 access solution, the Envoy™-8FE octal FE-to-POS/SPI controller, and the EtherMap™-3 mapper, PacketTrunk-4 enables rapid development of TDMoIP equipment.

PacketTrunk-4’s versatile features were chosen for fast, easy TDMoIP system design. The product’s TDM-side interface can accommodate four separate T1/E1 serial ports, each with a dedicated T1/E1 Channel Associated Signaling (CAS) interface, or one T3/E3/STS-1. A DPLL-based quad adaptive clock recovery block provides fast frequency lock and highly accurate phase tracking for each TDM port. The block achieves G.823/G.824-compliant jitter and wander performance under real-world PSN conditions by reconstructing the TDM clock based solely on inter-packet arrival time and jitter buffer fill level. During phase tracking, the chip optimizes jitter buffer levels to minimize latency and prevent buffer overflow or underflow.

PacketTrunk-4's payload processing block implements Constant Bit Rate (CBR) static allocation for circuit emulation, Variable Bit Rate (VBR) dynamic allocation for loop emulation, and HDLC for efficient transfer or termination of frame-based traffic. Payload size is selectable over a wide range, giving end users maximum tradeoff flexibility between latency and overhead.

Supported PSNs and encapsulation types include UDP/IP, MPLS, and switched Ethernet. VLAN tagging, priority labeling, and stacking per IEEE 802.1p and Q are also supported. PacketTrunk-4's PSN-side interface is an 802.3 Ethernet HDX/FDX MAC with a choice of MII, RMII, SMII, or SSMII interfaces.

“TranSwitch recognizes enormous potential in developing solutions for evolutionary convergence," stated Brian Stroehlein, TranSwitch Product Marketing Manager. "Evolutionary convergence involves transporting legacy services over next generation networks, as with PacketTrunk-4, and next generation services over legacy infrastructure, as with our EtherMap and Envoy products. PacketTrunk-4 is a key addition to our portfolio of evolutionary convergence products for access and edge networks."

“Packet-switched networks are not designed to provide TDM services,” explained Tal Gilad, TDMoIP Product Manager at RAD Data Communications. “TDMoIP enables transmission of TDM traffic over asynchronous networks while overcoming packet loss and delay variations introduced by those networks.” TDMoIP, developed by RAD and introduced to the industry at Telecom Geneva in 1999, is now an established technology that has been successfully deployed in over 15,000 ports worldwide to carry TDM over the packet-switched networks of carriers, Metropolitan Area Networks and enterprises.

PacketTrunk-4 is furnished with an RTOS-independent, hardware-abstracting, API-based device driver, evaluation kit, TDMoIP calculator spreadsheet, BSDL and IBIS models, and extensive documentation. The device is packaged in a 256-pin 27 x 27 mm Plastic Ball Grid Array (PBGA). Power supply voltages are 2.5v core and 3.3v I/O, and the chip is expected to consume about 1.2 W. PacketTrunk-4 is priced at $70 each in production quantities and will be sampling in December 2003.

http://www.transwitch.com/products/product/index.jsp?product=123 Attendees at ITU Telecom 2003 show in Geneva, Switzerland can also learn more by visiting TranSwitch at the USA Pavilion, Stand 1230.225 or RAD at Stand 2331.

Additional information on TDMoIP technology may be found at www.pseudowire.com.

TranSwitch Corporation, headquartered in Shelton, Connecticut, is a leading developer and global supplier of innovative high-speed VLSI semiconductor solutions - Connectivity Engines™ - to original equipment manufacturers who serve three end-markets: the Worldwide Public Network Infrastructure, the Internet infrastructure, and corporate Wide Area Networks (WANs). Combining its in-depth understanding of applicable global communication standards and its world-class expertise in semiconductor design, TranSwitch Corporation implements communications standards in VLSI solutions which deliver high levels of performance. Committed to providing high-quality products and service, TranSwitch Corporation, Shelton, CT is an ISO 9001:2000 registered company. Detailed information on TranSwitch products, news announcements, seminars, service and support is available on TranSwitch's home page at the World Wide Web site – http://www.transwitch.com.

Forward-looking statements in this release are made pursuant to the safe harbor provisions of the Private Securities Litigation Reform Act of 1995. Investors are cautioned that all 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 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 relating to TranSwitch’s indebtedness; 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. PacketTrunk, TEPro, Envoy and EtherMap are trademarks of TranSwitch Corporation.