MCI WorldCom Completes World's First Live Commercial Trial of Terabit per second Internet

DALLAS -- MCI WorldCom has successfully completed the industry's first live commercial trial of next-generation optical networking equipment from Nortel Networks* [NYSE/TSE: NT], setting the stage for a new era of networking. In the trial, MCI WorldCom successfully carried a Terabit of traffic per second on a single, hair-thin strand of fiber - sufficient capacity to enable one million 1-megabit multimedia connections. The late-December trial was staged carrying live Internet, voice and data traffic on the MCI WorldCom existing network span linking Dallas and Longview, Texas and relied on Nortel Networks' OPTera* LH backbone system and the OPTera 1600G optical amplification system.

The demonstration unequivocally showed the ability of the Nortel Networks open optical system and existing MCI WorldCom fiber to carry terabit-level traffic. "MCI WorldCom is committed to being on the leading edge, utilizing next-generation technology to meet the needs of our customers," said Fred Briggs, chief technology officer, Technology and Engineering, MCI WorldCom. "We are proud to enter the new Millennium as the first service provider to have trialed the world's fastest and highest capacity technology for backbone networking." "We see the explosive demand for bandwidth continuing to exceed the industry's broadest expectations ," said Greg Mumford, general manager, Optical Networks, Nortel Networks. "First-mover initiatives such as the introduction of terabit per fiber networking by Nortel Networks, and MCI WorldCom's leadership in trialing this technology are the kind of bold steps needed to move the industry forward in support of the high performance Internet." Nortel Networks announced its OPTera 1600G system in May 1999 for availability in 2000, and MCI WorldCom announced at that time plans for a live commercial trial of this new technology. The OPTera LH platform is commercially available now, and the OPTera 1600G optical amplification system will be available in early second quarter 2000.

The system, operating on a 10 Gbps platform, uses Dense-Wavelength Division Multiplexing to split the light into as much as 160 channels to maximize the capacity on each fiber. At maximum capacity, the OPTera 1600G system is capable of simultaneously transmitting 360,000 distribution quality versions of feature-length movies. Briggs explained that advances in capacity-per-fiber transmission on optical networks position MCI WorldCom to stay ahead of the exponential demand for the high-performance Internet resulting from the increasing usage of multimedia and e-business applications. The breakthrough technology will accommodate such applications as e-commerce and e-service, multimedia transmission and all other types of Internet traffic. "This technology will provide an unprecedented capacity per fiber for communication, collaboration and commerce, with signals traversing the nation in seconds," said Mumford. "We are driving the cost of networking down while maintaining the highest reliability levels in the industry." Industry analysts estimate the global market for optical networking will reach US $20 billion by 2002 based in growth in excess of 20 percent annually.

In September, 1995 MCI was first to commercially trial Nortel Networks' 10 Gbps system (OC-192) on the same Dallas to Longview, Texas route. Just over four years later, Nortel Networks and MCI WorldCom have moved the industry from gigabit per-fiber networking to terabit levels. In that space of time, Nortel Networks has become widely recognized as the world's leading supplier of high-capacity 10 Gbps SONET/SDH systems with over 90 percent global market share. Building on that experience in 10 Gbps networking, Nortel Networks has also led the industry in setting new benchmarks for open optical system capacities up to 1.6 Terabits per second on a 10 Gbps platform, and 6.4 Terabits per second on a scalable 40-80 Gbps platform. MCI WorldCom (NASDAQ: WCOM) is a global leader in communications services with 1998 revenues of more than $30 billion and operations in more than 65 countries.

MCI WorldCom's global networks provide high-capacity connectivity to more than 45,000 buildings worldwide. MCI WorldCom and Sprint have announced a merger agreement, which the companies expect to close in the second half of 2000, following regulatory and shareholder approvals. The new company will be called WorldCom. Nortel Networks is a global leader in telephony, data, wireless and wireline solutions for the Internet. The Company had 1998 revenues of US$17.6 billion and serves carrier, service provider and enterprise customers globally.

Today, Nortel Networks is creating a high-performance Internet that is more reliable and faster than ever before. It is redefining the economics and quality of networking and the Internet through Unified Networks* that promise a new era of collaboration, communications and commerce. The results or events predicted in these statements may differ materially from actual results or events. Factors which could cause results or events to differ from current expectations include, among other things: the impact of price and product competition; the dependence on new product development; the impact of rapid technological and market change; the ability of Nortel Networks to integrate the operations and technologies of acquired businesses in an effective manner; general industry and market conditions and growth rates; international growth and global economic conditions, particularly in emerging markets and including interest rate and currency exchange rate fluctuations; unanticipated impact of Year 2000 issues; and the impact of consolidations in the telecommunications industry. For additional information with respect to certain of these and other factors, see the reports filed by Nortel Networks with the United States Securities and Exchange Commission. Nortel Networks disclaims any intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise. *Nortel Networks, the Nortel Networks Globemark, Unified Networks, OPTera and How the world shares ideas are trademarks of Nortel Networks.