Copper Mountain and CoSine Communications Partner to Deliver Industry's First Integrated Solution for Advanced IP Services Over DSL.

Business Editors/High-Tech Writers

PALO ALTO, Calif.--(BUSINESS WIRE)--Feb. 29, 2000

Copper Mountain's CopperEdge DSL Concentrator and CoSine's IP

Service Delivery Platform Enable Service Providers to Offer

Value-Added Business Services Such as VPNs and Managed Firewalls

Copper Mountain Networks, Inc. (Nasdaq:CMTN), and CoSine Communications today announced the availability of the industry's first "IP intelligent edge" Digital Subscriber Line (DSL) solution that will enable service providers to deliver advanced IP services over DSL using their existing network infrastructures.

The two companies have successfully completed interoperability testing of Copper Mountain's CopperEdge(R) DSL concentrator and CoSine's IP Service Delivery Platform.

Unlike simple concentration implementations, the combined Copper Mountain/CoSine intelligent edge solution provides carriers with a cost-effective and scalable means of offering value-added services over DSL, including secure IP virtual private networks (VPNs) and managed firewalls, to tens of thousands of subscriber networks.

Now carriers can use DSL to provide secure IP VPNs in the same way that these services can be provided via private line, Frame Relay and dial access services. The CopperEdge DSL concentrator efficiently processes traffic and transmits it over Frame Relay or ATM to the CoSine IP Service Delivery Platform, where a variety of value-added IP services can be applied to each subscriber's network connection.

With the Copper Mountain/CoSine solution, carriers can leverage existing infrastructure to offer various VPN features that address a broad base of customer requirements, including the following:

--   Site-to-site VPNs: the ability to create secure VPN connections
     between offices

--   Remote-access, dial-up VPNs: the ability to create secure VPN
     connections for mobile workers

--   Extranets: the ability to create secure VPN connections for
     suppliers, partners and customers

Another value-added service that carriers can offer with this advanced IP intelligent edge solution is managed firewalls. Many small- and medium-sized businesses implementing DSL are migrating from analog or digital dial-up connections and are concerned with the heightened security risks associated with an "always-on" connection.

The Copper Mountain/CoSine solution provides network-based firewall services, a more scalable and manageable alternative to implementing customer premises equipment (CPE)-based firewall services.

Copper Mountain and CoSine also support IPSec encryption services today and plan to support additional enhanced security services over DSL, including intrusion detection and virus scanning for data traffic. CoSine provides best-of-breed security capabilities, licensed from Network Associates, to ensure that carriers always have the most robust and up-to-date security mechanisms in place for VPNs, firewalls and other services.

Copper Mountain's advanced CopperVPN capability further extends the performance of the CoSine IP Service Delivery Platform by aggregating hundreds of users onto a single virtual circuit. This significantly improves the scalability of the solution compared to any other DSL concentrator.

Carriers can provision any of the new Copper Mountain/CoSine-enhanced IP services without changing existing equipment or software at the customer site. The enhanced capabilities work with CopperRocket(R) CPE devices as well as third-party CopperCompatible(TM) CPE devices.

Cosine's IP Service Delivery Platform's unique ability to support tens of thousands of virtual routers, IPSec encryption services and Frame Relay over IPSec interworking allows carriers to offer differentiated DSL services in new markets with less investment in new equipment. Value-added services can be applied to DSL customer traffic and securely transported over the Internet to a central site.

"This is the first instance of a DSL concentrator with high IP intelligence and a network-based IP service delivery platform, creating a truly integrated access solution that service providers can use to deliver multiple enhanced services over a single broadband DSL loop," said Rick Gilbert, president and CEO of Copper Mountain. "CoSine has made network-based IP services a reality, and its platform offers the scalability, management and processing power required to deliver the next wave of value-added business Internet services. This really is a best-of-breed solution for service providers."

"By working together, Copper Mountain and CoSine have created a cost-effective, flexible and scalable IP-based solution that can deliver on-demand applications like VPNs and managed firewalls," said Dean Hamilton, CEO of CoSine. "As the market shifts toward new applications, service providers will require the IP-based class-of-service and security functionality that our joint solutions provide."

"The Copper Mountain and CoSine interoperability alliance makes sense for both companies," said Ron Westfall, a senior analyst at Current Analysis. "It allows each of them to expand their market opportunities and should prove mutually beneficial for both. Copper Mountain can counter the DSL concentrator/IP service edge offerings from its rivals, and CoSine enhances its recent expansion into the DSL market by partnering with an industry leader."

Copper Mountain and CoSine Equipment Solutions

Copper Mountain's CopperEdge DSL concentrators deliver bandwidth of up to 1.5 Mbps on a DSL line using a single copper pair, and up to 12 Mbps using inverse multiplexing (IMUX) technology, while supporting multiple services over DSL, including Internet access, toll-quality voice services, corporate VPNs and Frame Relay. The CopperEdge DSL concentrator's built-in layer-2 and layer-3 functionality enables carriers to deliver differentiated multi-tiered services to their customers and to ease service provisioning.

Cosine Communication's IP Service Delivery Platform includes the IPSX 9000(TM) non-stop IP service processing switch (a carrier-class switch capable of supporting tens of thousands of subscriber networks), the InVision(TM) Service Management System (SMS) and the InGage(TM) Customer Network Management (CNM) system. This platform enables Service Providers to create, manage and deliver value-added IP services to enterprise customers, who, in turn, can monitor and control their portion of the public IP network.

About Copper Mountain Networks

Copper Mountain Networks, Inc., (Nasdaq:CMTN) develops and markets a comprehensive family of DSL solutions that enable high-speed internetworking over existing copper facilities. The company's mission is to enable carriers and other service providers to offer a full range of high-performance, cost-effective data and voice services over DSL that are easy to deploy, use, and manage. Copper Mountain's CopperRocket(R) CPE family addresses the bandwidth, reliability, ease-of-use, and cost concerns of remote offices and users.

Its carrier-class CopperEdge(R) DSL concentrators and CopperView(TM) network management solutions offer a robust and scalable platform for carriers and multi-tenant-unit service providers to generate a high return on investment while satisfying the ever-increasing user demand for bandwidth.

Customers wanting more information about Copper Mountain products can contact Diana Helfrich at 650/687-3314 or visit the company's World Wide Web site at http://www.coppermountain.com. For investor relations information, call toll free 877-INFO-CMTN (463-6268) or contact the company at [e-mail].

About CoSine Communications

Founded in 1997 and based in Redwood City, Calif., CoSine Communications is the leading developer of managed IP service delivery platforms for Business IP service providers that risk losing profitability with today's low-value Internet access services. The CoSine solution enables Next Gen Telcos, Competitive IXCs, International Service Providers and PTTs to quickly and reliably turn up value-added services to their wholesale and retail subscribers.

For more information about CoSine, please contact Suzanne Panoplos at 650/637-4777 or visit the company website at www.cosinecom.com.

Portions of this release contain forward-looking statements regarding future events and are subject to risks and uncertainties. Copper Mountain wishes to caution you that there are some factors that could cause actual results to differ materially from the results indicated by such statements. These factors include, but are not limited to quarterly fluctuations in operating results attributable to the timing and amount of orders for our products, the concentration of our revenue in a small number of customers, factors affecting the rate of DSL deployment by our customers, market acceptance of our products, our ability to keep pace with rapidly changing product requirements, and factors affecting the demand for DSL technologies. We refer you to the documents Copper Mountain files from time to time with the Securities and Exchange Commission, specifically the section titled Risk Factors in our Registration Statement on Form S-1 (No. 333-73153).

Note to Editors: Copper Mountain and all Copper Mountain product names are trademarks of Copper Mountain Networks, Inc. All other marks are the property of their respective owners