Nortel Networks, Spirent Communications, AMCC to Demonstrate 10 Gigabit Ethernet WAN PHY Interoperability at Networld+Interop 2001.

Business Editors & High-Tech Writers

Networld+Interop Atlanta 2001

ATLANTA--(BUSINESS WIRE)--Sept. 11, 2001

Having completed a successful lab trial, Nortel Networks (NYSE:NT)(TSE:NT.), Spirent Communications, a wholly-owned business group of Spirent plc (NYSE:SPM), and AMCC (Nasdaq:AMCC) will unveil a live, routing switch-to-routing switch demonstration of OC-192 compatible, 10 Gigabit Ethernet (GbE) WAN PHY interoperability. This first-in-the industry showcase will be part of the 10 Gigabit Ethernet Alliance technology demonstration at Networld+Interop 2001 Atlanta (booth No. 2257).

In support of the developing IEEE P802.3ae draft standard, Spirent Communications has demonstrated the capability to generate and analyze 10GbE traffic over Nortel Networks Passport 8600 routing switch while operating with the AMCC chipset.

"Today's exhibition of true 10 gigabit Ethernet end-to-end metro connectivity and third party interoperability will further solidify Nortel Networks place as a frontrunner in driving and delivering standards compliant solutions," said Steve Schilling, president, Optical Ethernet, Nortel Networks. "We continue to expand our Optical Ethernet portfolio by working with companies like Spirent and AMCC to pave an efficient, low-cost way to bring 10 Gigabit Ethernet traffic with intelligence capabilities into the metro."

Nortel Networks previously demonstrated 10GbE capability on Passport 8600 at Networld+Interop 2001 Las Vegas. Nortel Networks will also support LAN PHY as specified in the IEEE 802.3ae draft standard as part of its complete solution set.

Spirent Communications was the first company to ship both LAN and WAN solutions for 10 Gigabit Ethernet. "Our AX/4000 is fulfilling its main function of accelerating time to market of 10GbE for our customers," said My Chung, president, Spirent Communications. "We are also very pleased to be involved in demonstrating the feasibility of 10GbE, itself an important step in the completion of the IEEE standard."

Nortel Networks, Spirent Communications and AMCC are leading the 10GbE standards as founding members of the 10 Gigabit Ethernet Alliance and members of the IEEE 802.3ae working group for WAN-compatible 10 gigabit Ethernet. Full approval of the IEEE 802.3ae draft standard is expected by spring 2002.

"Establishing 10G Ethernet interoperability between Nortel Networks Passport 8600 and Spirent's equipment proves that standards compliant 10G Ethernet systems can be designed today using commercial silicon such as the AMCC S19205 - Khatanga chipset," said Doug Spreng, president and chief operating officer, AMCC. "AMCC has been shipping 10G solutions for over a year now, and today's demonstration reinforces our leadership and commitment to provide complete standards compliant solutions for metro optical networking equipment."

Nortel Networks offers a full suite of Optical Ethernet technologies designed to redefine the performance and economics of enterprise networking by accelerating the transformation of metropolitan networks. These include DWDM (dense wavelength division multiplexing), 10 Gigabit Ethernet and RPR (resilient packet ring).

Complementing Nortel Networks Optical Ethernet solution, Passport 8600 is the first routing switch in the industry with software and hardware designed specifically for the rigorous scalability and reliability requirements of service providers. It can be used in campus and in-building backbone networks, or in service provider metro applications requiring higher performance, routing or metropolitan area network (MAN) connectivity. As part of Nortel Networks strategy to bring the power of 10-Gigabit networking into the metro environment, Passport 8600 delivers IEEE 802.3ae specifications-based, 10-Gigabit Ethernet and provides customers a fast, intelligent, cost-effective and scalable solution.

AMCC designs, develops, manufactures and markets high-performance, high-bandwidth silicon solutions for the world's optical networks. AMCC utilizes a combination of high-frequency analog, mixed-signal and digital design expertise coupled with system-level knowledge and multiple silicon process technologies to offer integrated circuit products that enable the transport of voice and data over fiber optic networks. The company's system solution portfolio includes PMD, PHY, framer/mapper, network processor, traffic management and switch fabric devices that address the high-performance needs of the evolving intelligent optical network. AMCC's corporate headquarters and wafer fabrication facilities are located in San Diego, California. Sales and engineering offices are located throughout the world.

Spirent Communications unites the best in performance analysis technology with network operations expertise. The company's award-winning solutions enable customers to accelerate the development, deployment and assurance of next generation network equipment and services worldwide.

Spirent Communications designs and manufactures Adtech, DLS, Edgcumbe, GSS, Hekimian, Net-HOPPER, SmartBits, TAS and Zarak products. More than 2,500 of the world's leading network and terminal equipment manufacturers, network service providers, corporate enterprises and test laboratories rely on our first-to-market products to verify and measure the performance and services of networks and communications devices.

Spirent plc is the parent of Spirent Communications. Spirent plc is listed on the London Stock Exchange (ticker: SPT) and on the New York Stock Exchange (ticker: SPM; CUSIP number: 84856M209), with one American Depositary Receipt representing four ordinary shares. Further information about Spirent plc can be found at www.spirent.com.

Nortel Networks is a global leader in networking and communications solutions and infrastructure for service providers and corporations. The Company is at the forefront of transforming how the world communicates, exchanges information and profits from the high-performance Internet through capabilities spanning the Optical Internet, Wireless Internet, Intelligent Internet and IP (Internet Protocol) technologies and services. Nortel Networks does business in more than 150 countries and can be found on the Web at www.nortelnetworks.com.

Certain information included in this press release is forward-looking and is subject to important risks and uncertainties. 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 severity and duration of the industry adjustment; the sufficiency of our restructuring activities, including the potential for higher actual costs to be incurred in connection with restructuring actions compared to the estimated costs of such actions; fluctuations in operating results and general industry, economic and market conditions and growth rates; the ability to recruit and retain qualified employees including at the most senior management levels; fluctuations in cash flow, the level of outstanding debt and debt ratings; the ability to make acquisitions and/or integrate the operations and technologies of acquired businesses in an effective manner; the impact of rapid technological and market change; the impact of price and product competition; international growth and global economic conditions, particularly in emerging markets and including interest rate and currency exchange rate fluctuations; the impact of rationalization in the telecommunications industry; the dependence on new product development; the uncertainties of the Internet; the impact of the credit risks of our customers and the impact of increased provision of customer financing and commitments; stock market volatility; the entrance into an increased number of supply, turnkey, and outsourcing contracts which contain delivery, installation, and performance provisions, which, if not met, could result in the payment of substantial penalties or liquidated damages; the ability to obtain timely, adequate and reasonably priced component parts from suppliers and internal manufacturing capacity; the future success of our strategic alliances; and the adverse resolution of litigation. For additional information with respect to certain of these and other factors, see the reports filed by Nortel Networks Corporation and Nortel Networks Limited with the United States Securities and Exchange Commission. Unless otherwise required by applicable securities laws, Nortel Networks Corporation and Nortel Networks Limited disclaim 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 logo, the Globemark and Passport are trademarks of Nortel Networks. Spirent and the Spirent logo are trademarks of Spirent plc.