Copper Mountain Announces Optimized DSL Efficiency and Voice Quality for Voice Over DSL Via Adaptive Fragmentation Features.

Business Editors/High-Tech Writers

PALO ALTO, Calif.--(BUSINESS WIRE)--May 16, 2000

Adaptive Fragmentation Allows More User Traffic per DSL Link,

Helps Expand Carrier Opportunities

Copper Mountain Networks, Inc., (Nasdaq:CMTN) the market-share leader in business Digital Subscriber Line (DSL) equipment, today announced that it has developed an innovative new technology called Adaptive Fragmentation, implemented in Copper Mountain's CopperEdge(R) DSL concentrators and CopperRocket(R) SDSL and IDSL customer premise equipment (CPE).

Adaptive Fragmentation greatly improves the efficiency and reduces the jitter and latency of voice services over Symmetric DSL (SDSL) and ISDN DSL (IDSL) networks. By minimizing the overhead in the DSL network, carriers using Adaptive Fragmentation increase the number of voice and data services that can be provisioned per link, retain high bandwidth efficiency, and ensure consistent toll-quality voice services even on lower speed DSL lines -- all contributing to increased carrier efficiency.

Adaptive Fragmentation provides much greater bandwidth efficiency than non-adaptive frame fragmentation or ATM (asynchronous transfer mode), which segments all data frames into short, fixed-length cells regardless of traffic mix. Non-adaptive frame fragmentation breaks long data packets into multiple smaller packets, in order to interleave voice packets and ensure low-delay, toll-quality voice. Adaptive Fragmentation, implemented by Copper Mountain Networks and its CopperCompatible(TM) CPE partners, performs fragmentation only when voice traffic is present, and only to the extent needed to meet voice delay tolerances, thereby retaining the higher bandwidth efficiency of longer data frames at all other times.

(Editor's note: For more information about Copper Mountain's voice capabilities, see another Copper Mountain announcement made today "Copper Mountain Enhances Voice over DSL Service Capabilities with New IP IQ Features".)

"Better voice quality, reduced overhead, and more efficient voice and data service translate into competitive advantage and greater profits for our carrier customers," said Rick Gilbert, president and CEO of Copper Mountain. "At Copper Mountain, we are continually developing innovations that make DSL networks more efficient, more effective, and more flexible."

"Copper Mountain's Adaptive Fragmentation feature allows Jato to better optimize the services we offer over DSL," said Mitchell Ashley, Jato's vice president of network integration. "By minimizing overhead, jitter and latency, Jato can optimize our network bandwidth to further ensure consistent data and voice services across all of our DSL line speeds. Copper Mountain's technical innovations keep Jato on the leading edge."

Adaptive Fragmentation: An Improvement to Segmentation and

Reassembly (SAR)

When voice packets are queued behind a large data packet using the SAR process, latency and jitter are created in the voice service. By fragmenting or segmenting the data packets, the latency and jitter of the voice service are controlled -- but at the expense of more overhead and wasted bandwidth. Unlike the SAR process employed by ATM, Adaptive Fragmentation maximizes the efficiency of the bandwidth between CPE and CopperEdge concentrators by fragmenting long data packets into smaller packets only when voice is present on the line. Adaptive Fragmentation is dynamic, employing a look-ahead buffer to see voice traffic coming and then fragmenting data from the subscriber's Ethernet LAN into variable-sized packets.

The SAR process of ATM always fragments packets to 48 byte cells. However, the latency and jitter associated with long data packets actually depends on the speed of the DSL link. For example, a long data frame will traverse a high-speed 1.5 Mbps DSL link in 8 milliseconds, but the same data frame may take 80 milliseconds to traverse a 160 kbps DSL link. Therefore, very little fragmentation is necessary at higher speeds, while at lower speeds, a large data frame should be segmented into many fragments. The fragmentation is adaptive; it coordinates with the CPE and adjusts the amount of fragmentation based on the speed of the DSL link.

Because Adaptive Fragmentation is implemented in Copper Mountain CPE and Copper Compatible CPE at the subscriber side and in the CopperEdge(R) concentrator at the central office (CO), it is transparent to subscribers as well as to service providers' networks. Adaptive Fragmentation can be used to optimize DSL transmission of IP-based voice, PPP traffic, and IP or MAC encapsulated data traffic.

"This is a clever means of optimizing the tradeoffs between minimizing jitter, latency, and overhead when providing packet-based voice service," said Scott Bradner, senior technical consultant at Harvard University. "Automatically fragmenting non-real-time data when real-time data is present optimizes the best of both worlds."

Adaptive Fragmentation Part of CopperVIP Program

Adaptive Fragmentation technology is part of Copper Mountain's CopperVIP(TM) -- or Voice In Packets -- Initiative, an extension of Copper Mountain's industry-leading CopperCompatible program that facilitates and accelerates the development of products that are interoperable with Copper Mountain DSL concentrators. A number of CopperCompatible partners are implementing Adaptive Fragmentation in their products, including ADTRAN, Efficient Networks, Netopia, Pivotal Networks, Ramp Networks, Woodwind Communications, and Xpeed.

"ADTRAN views Copper Mountain's innovative Adaptive Fragmentation technology as critical to the future success of voice over DSL deployment," said Danny Windham, general manager of the ADTRAN Enterprise Networks Division. "That's why ADTRAN is adopting the technology into its market-leading line of IADs to develop the most robust, field-proven DSL Concentrator-to-IAD offering available."

"Netopia expects that Copper Mountain's new Adaptive Fragmentation technology will be very popular with service providers and end customers," said Michael Trupiano, senior vice president and general manager, Netopia Internet Equipment Division. "By increasing the number of voice and data services that can be provisioned on a DSL connection, Adaptive Fragmentation should substantially enhance the cost-effectiveness of voice over DSL."

"Voice is one of the key value-added services to be delivered over broadband networks," said Raghu Bathina, vice president of product management for Ramp Networks, a leading provider of easy-to-use, shared Internet access devices. "Copper Mountain's Adaptive Fragmentation is an important implementation because it ensures that carriers can provide toll-quality voice services on frame-based DSL networks. Ramp Networks has included Adaptive Fragmentation support on its recently announced WebRamp 2000V SDSL integrated access device, enabling small office customers to significantly reduce the cost of voice and data service relative to traditional access methods without compromising voice quality."

"Interoperability is a major focus of Woodwind's DSL access solution for service providers," stated Brian Hardy, CTO of Woodwind. He added, "We fully support Copper Mountain's innovative Adaptive Fragmentation technology and are delighted to participate as a CopperCompatible CPE Partner."

"Xpeed believes this Adaptive Fragmentation feature is an innovative solution to ensuring timely transfer of voice and data packets over DSL Networks," said Richard D'sa, vice president of sales and marketing at Xpeed Networks. "This should enable service providers to attain toll quality voice services."

Copper Mountain's CopperVIP program also facilitates interoperability of CPE, Integrated Access Devices (IADs), and Integrated Communications Platforms (ICPs) with voice solutions from Copper Mountain partners, including CopperCom, Jetstream Communications, Lucent Technologies, and TollBridge Technologies. Adaptive Fragmentation provides the capability and voice quality that is recommended in Annex B of the draft Voice over DSL (VoDSL) specification from the DSL Forum, and provides efficiency and performance benefits for both Voice over IP (VoIP) and AAL2 VoDSL gateway solutions.

Copper Mountain Multi-Service Solutions

Copper Mountain engineered its CopperEdge DSL concentrators to have the flexibility and intelligence needed to support multiple types of DSL concurrently, including SDSL, IDSL, G.lite, and turbo-charged G.lite. The CopperEdge provides bandwidth of up to 3 Mbps on a DSL line using a single copper pair, and up to 12 Mbps using inverse multiplexing (IMUX) technology. In addition, Copper Mountain's CopperEdge DSL concentrators support multiple services over DSL, including Internet access, toll-quality voice services, corporate virtual private networks (VPNs), and Frame Relay. This multi-service capability enables service providers to differentiate their service offerings, enhance revenues, and retain customers. CopperView(TM) network management tools provide configuration, fault analysis, and performance monitoring throughout the network from the carrier's central operations center, resulting in substantial savings in time, cost, and complexity in managing DSL equipment network-wide.

Price and Availability

Adaptive Fragmentation will be available as a standard feature on all Copper Mountain CopperEdge DSL Concentrators and CopperRocket SDSL and IDSL CPE in July, 2000.

About Copper Mountain Networks

Copper Mountain Networks, Inc., (Nasdaq:CMTN) develops and markets a comprehensive family of Digital Subscriber Line (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 CopperEdge(R) DSL concentrators, OnPrem(TM) multi-tenant unit (MTU) 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 1.877.INFO.CMTN (463.6268) or contact the company at [e-mail].

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 Annual Report on Form 10-K for the year ended December 31, 1999 and other reports and filings made with the Securities and Exchange Commission.

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.