Cerent and Optical Networks Announce Interoperability Between Advanced SONET and Optical Networking Platforms.

SAN JOSE, Calif.--(BUSINESS WIRE)--May 27, 1999--

SUPERCOMM 99, Booth No. 7773

Achievement Gives Carriers More Options in Meeting High-Capacity

Bandwidth Demands -- Demonstration Featured at SUPERCOMM `99

Cerent Corporation and Optical Networks, Inc. today announced that they have successfully tested interoperability between the Cerent 454, the first evolutionary optical transport platform, and Optical Networks' metropolitan optical transport platform, the Dynamic Transport System(TM)(DTS(TM)).

This testing highlights the benefits of direct connection of Cerent and Optical Networks' equipment in next-generation optical solutions. This architecture appeals to service providers because it allows them to cost-effectively aggregate traditional DS1 and DS3 SONET traffic, as well as data-centric services, like Gigabit Ethernet and video onto a single optical fiber. Such optical solutions enable large amounts of network traffic to be easily routed and managed in the optical domain, greatly reducing deployment costs and simplifying network operations.

"With the DTS and the Cerent 454, we have created a better solution than any established network equipment vendor could offer," said Hugh Martin, CEO of Optical Networks. "Cerent technology and products have turned transport pricing curves upside down. Now with the addition of the DTS, we have created an even more compelling value proposition for carriers."

"Service providers are craving scalable, cost-effective solutions that allow their optical transport networks to evolve," said Carl Russo, president and CEO of Cerent. "The combination of the Cerent 454 and DTS delivers all of this, plus both services and bandwidth on demand."

The interoperability testing was accomplished by operating the Cerent and Optical Networks' equipment in a configuration typical of that encountered in many service provider networks. The Cerent 454 was equipped as a SONET ring operating at an OC-48 line rate and directly delivering services, including DS1 and Gigabit Ethernet. This SONET traffic was transported error-free across the optical backbone composed of the Dynamic Transport Systems equipped in a ring configuration.

The Cerent traffic was mapped onto a single wavelength, sharing the fiber with other channels carrying assorted data traffic on other wavelengths. A variety of network failure scenarios were simulated to ensure seamless interworking of optical layer and SONET service protection mechanisms.

"By accomplishing interoperability at this level, Cerent and Optical Networks are telling service providers that they have an effective means of handling both next-generation SONET requirements and migrating to an optical network infrastructure," said Mat Steinberg, director of Optical Networking at RHK (Ryan Hankin Kent, Inc.).

Optical Networks and Cerent will demonstrate this interoperability in a live network simulation at the SUPERCOMM '99 Telecommunications Conference and Exhibition, June 8-10, in Booth No. 7773 at the Georgia World Conference Center in Atlanta.

About Cerent

Cerent Corporation is the revolutionary network element delivering next generation transport solutions today. While demand for network access skyrockets and the core networks are rapidly expanding, SONET transport networks are the next critical bandwidth bottleneck. Traditional SONET equipment is designed for voice networks and cannot accommodate the surging data traffic unleashed by the Internet. The Cerent 454 is the first evolutionary optical transport platform that supports any network traffic type over any optical bit rate at 50 percent lower cost than traditional SONET solutions.

Over 50 service providers throughout the U.S. and Canada have deployed the Cerent 454 since its introduction in December 1998. Cerent customers are service providers (such as National Carriers, ILECs, CLECs, IXCs, Utilities and Cable TV providers) who demand simple, scaleable and efficient transport systems that fit today's SONET infrastructure. Cerent products solve the transport bottleneck and evolve to the optical networks of the Internet era. Information about Cerent can be found at: http://www.cerent.com.

About Optical Networks

Optical Networks combines state-of-the-art optical transport systems with data networking technology to deliver true optical networks. These networks will fulfill the promise of wavelength-routed services, while solving the practical issues facing Metro Operators today. The Company will demonstrate its Dynamic Transport System at SUPERCOMM '99. Visit Optical Networks' Web site at www.opticalnetworks.com.

Note to Editors: Cerent and Cerent 454 are trademarks of Cerent Corporation. The Optical Networks logo, Dynamic Transport System, DTS, ONLINE, OLMP and OPTX are trademarks of Optical Networks, Inc.