Mpower Expands Relationship With Copper Mountain; Extending Service Reach in Metro Markets.

Business Editors/High-Tech Writers

PALO ALTO, Calif.--(BUSINESS WIRE)--Oct. 11, 2001

MpowerOffice(SM) Service Offering Utilizes Copper Mountain T1 Solution

to Deliver High-Speed Internet Access and Voice Services to Business

Customers At Any Distance From

Copper Mountain Networks, Inc. (Nasdaq:CMTN), a provider of intelligent broadband access solutions, today announced that Mpower Communications (Nasdaq:MPWR), a provider of broadband high-speed Internet access and voice services to business customers, has deployed Copper Mountain's CopperEdge(R) T1 line cards to extend the reach of its services in major metro markets. Copper Mountain's CopperEdge T1 line card enables delivery of broadband services to customers at any distance from a central office (CO). Mpower recently installed CopperEdge T1 line cards in its previously deployed CopperEdge 200 Concentrators to launch its new MpowerOffice(SM) integrated voice and Internet services for small and mid-size business customers in Atlanta and Chicago. Mpower plans to expand MpowerOffice to all of its existing major metropolitan markets throughout the nation. (Note to Editors: Please see the other press release Mpower issued on August 29, 2001: "Mpower Communications Launches New Integrated Broadband Platform.")

"Mpower is a leader in developing and delivering broadband data and voice services that meet the needs of small and medium-size businesses," said Rick Gilbert, president and CEO of Copper Mountain Networks. "Copper Mountain has worked closely with Mpower to develop solutions that enable cost-effective delivery of broadband services to Mpower's customers. We're pleased to support Mpower as they extend the reach of their business-class broadband services."

"Copper Mountain's solutions enable us to deliver copper-based, high-speed Internet and voice services to business customers at any distance from a wiring center or digital loop carrier," said Joe Wetzel, president of Mpower Communications. "By combining the reach of Copper Mountain's T1 line cards with the advanced provisioning capabilities of Copper Mountain's CopperEdge 200 Concentrators, we can deliver services that are highly cost-effective, and easily scalable."

About the CopperEdge(R) T1 Line Card

Copper Mountain's 12-port CopperEdge T1 Line Card is hot-swappable in CopperEdge Concentrators, and can be deployed concurrently in the same chassis with Copper Mountain's CopperEdge Full-Rate ADSL, G.lite, IDSL, and SDSL line cards. The CopperEdge T1 line card enables broadband service providers to leverage CopperEdge concentrators' IP service intelligence to deliver cost-effective broadband voice and high-speed data services, even to customers who are beyond the reach of conventional SDSL services or who are served by Digital Loop Carrier (DLC) equipment. The CopperEdge T1 line card is interoperable with Copper Mountain's CopperRocket(R) 508T integrated access device (IAD), as well as industry-standard T1 customer premise equipment (CPE).

About Mpower Communications

Mpower Communications is a subsidiary of Mpower Holding Corporation (Nasdaq:MPWR). A facilities-based broadband communications provider, Mpower offers a full range of data, voice, Internet access, and Web hosting services for small and medium-size business customers. Mpower operates in 28 markets in the states of California, Nevada, Texas, Illinois, Ohio, Michigan, North Carolina, Georgia, and Florida. Further information about the company can be found at www.mpowercom.com.

About Copper Mountain Networks

Copper Mountain Networks, Inc. (Nasdaq:CMTN) is a leading provider of intelligent broadband access solutions for carriers and service providers. The company offers a broad set of DSL and aggregation equipment for central office, digital loop, and multi-tenant unit (MTU) networks worldwide. These products enable efficient and scalable deployment of advanced voice and data services while leveraging existing network infrastructures, reducing both capital and operational costs. Copper Mountain's products have been proven in some of the world's largest broadband network deployments. For more information please visit the company's World Wide Web site at http://www.coppermountain.com.

Portions of this release contain forward-looking statements regarding future events and are subject to risks and uncertainties; such factors could affect future revenue and earnings. 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: rapid changes in the service provider landscape and among our CLEC customer base, quarterly fluctuations in operating results attributable to the timing and amount of orders for our products, factors affecting the rate of DSL deployment by our customers, market acceptance of our products, the concentration of our revenue in a small number of customers, our ability to penetrate the international, multi-tenant unit (MTU), and the incumbent telecommunications service provider (ILEC/IXC) market, risks related to our rapid growth, 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, 2000 and other reports and filings made with the Securities and Exchange Commission.

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.

Mpower Forward-Looking Statements

Under the safe harbor provisions of the Private Securities Litigation Reform Act of 1995, Mpower Communications cautions investors that certain statements contained in this press release that state Mpower Communications and/or management's intentions, hopes, beliefs, expectations or predictions of the future are forward-looking statements. Management wishes to caution the reader these forward-looking statements are not historical facts and are only estimates or predictions. Actual results may differ materially from those projected as a result of risks and uncertainties including, but not limited to, projections of future sales, market acceptance of our product offerings, our ability to secure adequate financing or equity capital to fund our operations and network expansion, our ability to reduce our outstanding indebtedness, our ability to manage rapid growth and maintain a high level of customer service, the performance of our network and equipment, the cooperation of incumbent local exchange carriers in provisioning lines and interconnecting our equipment, regulatory approval processes, changes in technology, price competition and other market conditions and risks detailed from time to time in Mpower's Securities and Exchange Commission filings.