Excel Announces New IP Telephony Enhancements to Its ONE Architecture Family of Products.

LAS VEGAS--(BUSINESS WIRE)--April 14, 1999--

Excel Switching Corporation (NASDAQ:XLSW), a leading provider of open telecommunications platforms for voice and data networks worldwide, announced today at Voice on the Net '99 (Booth # 605) that it has added comprehensive Internet Protocol (IP) transport and signaling capabilities to the ONE Architecture(TM) family of scalable open programmable telecom solutions. With the addition of the new Voice Data Access Concentrator (VDAC) card to the EXS family of programmable switching platforms, Excel offers Voice over IP (VoIP) New World packet technologies to its extensive portfolio of partner-produced enhanced service applications and Excel's Open Infrastructure Tandem and End-Office switching solutions.

The VDAC card is the first product to be announced as part of Excel's strategy for Next- Generation network solutions. (See related news release: Excel Announces the EXS Media Gateway.) The VDAC card is integrated into the EXS platform at the EXS Signaling layer allowing application developers and Excel's infrastructure solutions customers to easily and quickly IP enable the EXS based solutions. With this platform, incumbent and next-generation carriers are able to leverage Excel-based solutions, to combine the best of "New World" IP based technologies and "Old World" Public Switched Telephony Network (PSTN) features and services.

"By extending our programmable technology to the VoIP space, Excel and its partners form a unique solution that can offer open carrier-grade solutions to Next Generation carriers," said Robert Madonna, president and CEO of Excel. "Our commitment to open and programmable technology makes it possible for incumbent and emerging carriers to deploy differentiated services - regardless of current or future network technology."

VDAC is a modular IP packet engine interface card which can provide 160 channels of VoIP over dual 100MB Ethernet interfaces, when inserted into Excel's carrier class EXS platform. Implemented with Excel's flexible and patented Programmable Protocol Language (PPL) Technology to customize PSTN protocols and offer unmatched flexibility to Next Gen IP networks, the VDAC card is designed with the latest generation Digital Signal Processors (DSPs), microprocessors and integrated components to offer future proof IP vocoding algorithms and IP protocol support.

Excel's open gateways are able to support multiple PSTN and IP protocols in a single system, by leveraging Excel's EXNET fiber optic network. The EXS platform can scale up to 14,400 of VoIP and 14,400 PSTN circuits in a single non-blocking architecture. A single fully redundant EXS 2000 9U 19" NEBS-III shelf can be configured for 960 VoIP channels and corresponding PSTN circuits including a full array of PSTN signaling protocols such as SS7 and ISDN and DSPs for general telephony tone treatments, conferencing and announcements.

Excel's multi-protocol capability and open architecture product are a cost-effective solution for carriers to deploy a wide range of services and applications and require minimal software changes with new or enhanced network protocols for either the PSTN or IP networks. Excel's comprehensive IP transport and signaling capabilities will enable Excel Partners to quickly provide new services regardless of the mix of circuit-switched or IP interfaces in a carrier's network. Excel's solution will enable carriers to continue to generate revenues as they make the transition to new technologies as their IP-based networks evolve.

"With Excel's industry leading open programmability and new VoIP technology, we can offer enhanced services applications to any carrier -- regardless of their network architecture or protocol requirements," said Jeff Paine, vice president of marketing for Magellan Network Systems. "It opens up new markets for our existing product while giving us a proven platform to offer new IP and Web-enabled services."

With over 150 developers, Excel supports a large portfolio of third party, telco-grade features and services in the telecommunications market today. Applications available from Excel Partners and developers include: unified messaging; prepaid calling and calling cards; Surf'n Call; Web enabled call centers; voice activated dialing; text-to-speech & speech-to-text; Remote Access Servers (RAS) personal assistants and messaging agents.

About ONE Architecture

ONE Architecture defines Excel's strategic technology framework for its state-of-the-art Expandable Switching System (EXS). It enables carriers and developers to integrate network routing, enhanced services and media support on a single, highly-scalable switching platform. With its product and services, Excel provides a scalable network solution regardless of legacy signaling protocols, switching capacity, or billing and subscriber services offered from the PSTN (Public Switch Telephone Network) switch.

About Excel Switching Corporation

Excel Switching Corporation is a leading provider of open switching platforms for telecommunications networks worldwide. Excel develops, manufactures, markets and supports a family of open, programmable, carrier-class switches that address the complex enhanced services and wireless and wireline infrastructure needs of network providers. Excel's products are currently deployed in telecommunications networks worldwide. Visit Excel's Web site at http://www.xl.com.

This release may contain statements which are "forward looking," and is subject to risks and uncertainties that could cause actual results to differ significantly from expectations. Factors that might cause such a difference include, but are not limited to, those relating to Excel's highly competitive market; dependence on and concentration of relationships with application developers, original equipment manufacturers and systems integrators; evolving market for telecommunications services and rapid technological change; possible delayed or lengthy sales cycles; risks associated with concentrated product family and new product introductions; Excel's dependence on its proprietary rights; and other risks identified in the Company's Securities and Exchange Commission filings including those risks identified in the section entitled "Risk Factors" of the Company's Annual Report for the year ended December 31, 1998 on Form 10-K. Product and service names used within are trademarks, registered trademarks and service marks of their respective owners.