Excel Receives $1.3 Million Order From Transaction Network Services.

HYANNIS, Mass.--(BUSINESS WIRE)--Feb. 4, 1998--

Company's Programmable Switches at Core of Expanding Data Network

Excel Switching Corporation (Nasdaq:XLSW) announced today that Transaction Network Services, Inc. (TNS), a provider of data communications services for transaction-oriented applications, has placed a one-year, $1.3 million order to continue integrating Excel's programmable switches in the expanding TNS network. The order is in conjunction with TNS' accelerated expansion plan to increase its current number of locations from 8 to 23 in 1998.

"The scalability and density of Excel's programmable switching infrastructure provides TNS with significant economies of scale and greatly reduces the operating costs associated with this type of network expansion," said Rick Sternitzke, Chief Technical Officer of Transaction Network Services.

TNS utilizes Excel's LNX programmable switch for the infrastructure of its point-of-sale network, which establishes fast and efficient data transport for credit card processing to a blue chip customer list including First Data Corporation, EPS/Buypass, and Alliance Data Systems. TNS utilizes the Excel switch for trunk aggregation from Local Operating Companies (LOCs) and from some Inter Exchange Carriers (IXCs). The Excel LNX provides TNS with a cost effective means of aggregating trunks from a large number of carrier switches and directing that traffic to custom TNS call-handling equipment.

"We are pleased that Transaction Network Services continues to use the Excel switch as the foundation of their network," said Russell Levesque, Vice President of Product Management at Excel Switching Corporation. "Because the TNS application supports high-volume financial transactions, their selection of Excel for this mission critical application speaks to the functionality and reliability of our product design. TNS is also a prime example of how Excel's customers can quickly, easily, and cost effectively expand their networks."

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 in almost 60 countries throughout the world.

Transaction Network Service, Inc.

Transaction Network Services, Inc., headquartered in Reston, Virginia, provides data communications services for transaction-oriented applications. The company is listed on the NASDAQ National Market under the symbol TNSI. Additional company information is available on the TNS website at www.tnsi.com.

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This release may contain statements which are "forward looking". Such statements are 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: Excel Switching Corp.

Karen Steele, [phone]

e-mail: [e-mail]

website: www.xl.com

or

FitzGerald Communications

Chris Nahil, [phone]

e-mail: [e-mail]