Excel and XNT Successfully Deploy 8K Port Tandem/International Gateway Switch.

HYANNIS, Mass.--(BUSINESS WIRE)--May 7, 1998--Excel Switching Corporation (NASDAQ:XLSW) announced today that XNT Systems, Inc. has successfully deployed Excel's EXS Expandable Switching System for an international carrier based in metropolitan New York. The carrier is utilizing the system to provide long distance, prepaid, and calling card services to its rapidly growing customer base, and has taken advantage of Excel's open and scalable architecture to quickly scale up to its current 8,000 port capacity switch. EXS systems can be configured to support over 30,000 non-blocking ports in a single switch.

XNT Systems delivers the intelligent switch control and comprehensive call processing functions that have allowed the EXS installation to rapidly grow from a few hundred ports to the 8,000 port capacity system. The distributed switching architecture of the EXS system enables service providers to offer network based services in a scalable, tightly integrated solution, and to grow their operations incrementally as their traffic needs require. The XNT/Excel platform in New York has recorded throughput of over one million minutes per day on this high-reliability switch. With the level of scalability in the platform, the carrier has been able to quickly and cost effectively enter the market and capture target opportunities, and then seamlessly grow its capacity while still in service.

XNT Systems has been delivering telecommunication solutions to the long-distance carrier marketplace since 1993 and offers extensive enhanced services through its Smart Connections modules. XNT also supports highly specialized providers with operator services modules for both wireless and wireline markets. "Building on Excel's EXS has enabled us to maximize our customer's investment through the development of a scalable, robust, high-traffic architecture. Our use of advanced switching technology is one example of our commitment to the business visions of our customers," said Nick Toumpas, President of XNT.

Excel's ONE Architecture product strategy addresses the growing demand for scalable, multi-service platforms that can simultaneously support wireline and wireless infrastructure switching as well as multiple enhanced services. "XNT is one of the companies at the forefront of bringing competitive infrastructure solutions to service providers," said Robert Madonna, President and CEO of Excel Switching Corporation. "The XNT deployment in New York is an example of how service providers are benefiting from Excel's open and scalable architecture."

About XNT

XNT Systems offers complete turnkey solutions to network operators, enhanced service providers and value added resellers of operator and directory assistance applications worldwide. XNT has succeeded in developing products based upon customer requirements in the areas of capacity and functionality. The company has opened new doors of opportunity to its customers for expansion of their already successful businesses, while offering innovative solutions to broad new market segments. More information about XNT may be obtained from its website at www.xntsys.com. XNT will be presenting at Supercomm in Atlanta in June of 1998 and Voice Europe in October.

About Excel

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. The company's products are currently deployed in telecommunications networks in almost 60 countries throughout the world. Excel has ISO 9001 certification and BABT Full Quality Assurance Approval. Visit Excel's website at http://www.xl.com.

-0-

This release may contain statements which are "forward looking", 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: dependence on and concentration of relationships with application developers, original equipment manufacturers and systems integrators; length of sales cycle; risk of new product introductions; highly competitive market; compliance with evolving industry standards; dependence on 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 Registration Statement on Form S-1 (File No. 333-35791) and Quarterly Report on Form 10-Q for the quarter ended September 27. 1997.

CONTACT: XNT

John Herlih

[phone]

[e-mail]

or

Excel Switching Corporation

Karen Steele

[phone]

[e-mail]

or

FitzGerald Communications

Wendy Pickering

[phone]

[e-mail]