DSET Gateway Connects Network Telephone with BellSouth

Bridgewater, NJ - April 4, 2001 - (Nasdaq: DSET) - DSET Corporation announced today that Network Telephone Corp., the Southeast U.S. leading provider of bundled local, long-distance and high-speed DSL Internet services for businesses, is now using DSET's ezLocal gateway to order lines for customers from BellSouth.

The DSET ordering gateway is part of an integrated suite of software solutions and services that Network Telephone purchased last year. In addition, DSET has provided program-management, installation, configuration, interoperability testing, and training services to Network Telephone's $12 million automated back-office system.

"The implementation and integration of DSET's electronic data interface (EDI) between Network Telephone and BellSouth marks a milestone in the deployment of our highly automated OSS," said Vincent M. Oddo, executive vice president and chief information officer at Network Telephone. "Utilizing the DSET gateway increases our efficiency and eliminates the likelihood of human error, helping Network Telephone to become the leader in timely and error-free order fulfillment."

"The interconnection between Network Telephone and BellSouth emphasizes the critical role of electronic bonding in the success of competitive telecom providers," said Jeff Gill, DSET's vice president of professional services. "Competitive carriers cannot afford to operate without the efficiency and cost-effectiveness inherent to electronic bonding with trading partners. And as shown by the size of DSET's customer base, carriers across the U.S. recognize that we offer the most capabilities and lowest risk when it comes to buying gateways and, more importantly, moving them to production."

About Network Telephone:

Network Telephone Corp. is a facilities-based integrated communications provider (ICP) using voice over digital subscriber line (VoDSL) technology to deliver local, long-distance, high-speed Internet, Web site development tools and hosting, and applications services to small- and medium-sized businesses throughout the Southeast U.S. During 2000, the company grew from 150 employees to a current count of more than 700 at its headquarters and 24 regional sales offices. Network Telephone has raised $195.5 million in equity and $140 million in debt, which fully funds the company's aggressive business plan. Network Telephone currently has more than 30,000 access lines in service. For more information about Network Telephone, visit the company's Web sites at www.networktelephone.net and www.powerlinedsl.net.

About DSET:

DSET Corporation is a leading supplier of software and services that enable telecommunications providers to implement electronic Trading Partner Networks, which significantly reduce the time required to provision services for customers and resolve service outages to maintain high service quality and ensure customer retention. DSET is headquartered in Bridgewater, New Jersey, and the company's Web site can be viewed at www.dset.com.

Statements regarding financial matters contained in this press release, other than historical facts, are forward-looking. Since all statements about DSET's plans, estimates, and expectations are based on current projections that involve risks and uncertainties, and are subject to change at any time, the company's actual results may differ materially from expected results. Investors should consider these risks and uncertainties, which are discussed in documents filed by DSET with the Securities and Exchange Commission. These documents identify important factors that could cause the actual results to differ materially from those contained in the projections or forward-looking statements. DSET expressly disclaims any obligation to update any forward-looking statements.

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DSET Contacts:

Media Relations: Dean Maskevich, Marketing Communications, 908-526-7500 Ext. 1366,
e-mail: dmaskevi@dset.com

Investor Relations: John P. Murphy, Westfield Investor Relations, 908-233-1558, e-mail: westfieldir@worldnet.att.net

Network Telephone Contacts:

Clare LaGrand, Network Telephone Corp., 850-469-9904 ext. 1505, e-mail: clare.lagrand@networktelephone.net

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