Laurie Falconer Centillium Communications, Inc. (510) 771-3647 [email protected]

CENTILLIUM AND EFFICIENT DEMONSTRATE INTEROPERABILITY OF FULL-RATE ADSL PRODUCTS

Four-Port, Multi-Mode Centillium CopperFlite™ Chipset Passes Physical-Layer Interoperability Tests with SpeedStream™ Modems from Efficient Networks

FREMONT, Calif., January 24, 2000 - Centillium Communications, Inc., today announced that the CopperFlite™ Asymmetric Digital Subscriber Line (ADSL) Central Office chipset has achieved Full-Rate G.dmt (ITU G.991.1) and ANSI T1.413 Issue 2 interoperability with SpeedStream modems from Efficient Networks, Inc. The interoperability tests verified physical-layer connectivity between DSLAM line cards based on CopperFlite chipsets and SpeedStream modems based on Alcatel’s DynaMiTe ADSL chipsets. Centillium and Efficient had previously announced ADSL G.lite (ITU G.922.2) interoperability between Centillium’s eight-port CopperLite chipset and SpeedStream modems.

"Successful interoperability with SpeedStream modems helps assure our telecom customers that ADSL line cards based on the CopperFlite chipset will operate with any multi-vendor ADSL equipment based on the Alcatel ADSL chipset," said Faraj Aalaei, co-founder and vice president of marketing for Centillium Communications. "Efficient Networks, the leading supplier of ADSL CPE to telecom companies worldwide, recognizes the need for standard interoperability across the ADSL industry, and we are pleased to work closely with them to conduct these critical tests."

"Efficient Networks tested several SpeedStream modems and routers with four-port network access line cards based on Centillium’s multi-mode chipset," said Greg Langdon, executive vice president of product strategy for Efficient Networks. "We found that our Alcatel chipset-based modems are fully compatible with Centillium’s CopperFlite chipset in both Full-Rate and G.lite modes of operations."

Centillium CopperFlite CO Chipset Solution
Centillium's CopperFlite CO chipset (CT-L50SC04) is the industry's highest performance, most flexible, and lowest power-dissipation ADSL solution. CopperFlite consists of just two chips, the CopperFlite CT-L50AC04 analog front end (AFE) and the CopperFlite CT-L50DC04 digital signal processor (DSP). This solution offers a complete suite of silicon and software features, including Utopia Level-2, bit synch, and PCM bus for DSLAM, DLC, and MDU applications.

CopperFlite supports either Full-Rate or G.lite industry standards, including ITU G.992.1 (G.dmt), ITU G.992.2 (G.lite), or ANSI T1.413 Issue 2. For Full-Rate ADSL, CopperFlite enables end users to connect to the Internet at speeds up to 8.192 Mbps downstream and up to 1024kbps upstream, depending to the loop and the reach conditions. For G.lite ADSL, CopperFlite supports connection rates up to 1.536Mbps downstream, and up to 512Kbps upstream, complying with G.992.2 standards. Interoperability with both Full-Rate and G.lite customer premises equipment has been verified in multi-vendor environments.

CopperFlite Chipset is Pin-to-Pin Compatible with CopperLite Chipset
CopperFlite is fully pin-to-pin and software compatible with Centillium’s eight-port CopperLite ADSL G.lite solution (CT-L21SC08). This provides a single development platform that can branch into multiple products, including G.lite-only line cards, Full-Rate-only line cards, or some combination of the two standards. DSL systems manufacturers can now design line cards that allow network service providers to offer multi-tiered DSL services. Service providers can address mass consumer markets with very high-port density line cards, based on the CopperLite chipset, with the flexibility of using lower density multi-mode line cards, based on the CopperFlite chipset, for business markets or central office locations where rack space is less stringent.

About Efficient Networks
Efficient Networks, Inc., is a leading provider of broadband access products that employ digital subscriber line (DSL) technology. Emphasizing ease of use, the company's SpeedStream family of DSL products provides high-performance remote access for small and medium businesses, branch offices, telecommuters, and consumers. Working in partnership with DSL service providers worldwide, Efficient is enabling a new generation of broadband applications today. Efficient Networks is based in Dallas, Texas, with sales and support locations around the world. For more information, visit www.efficient.com.

About Centillium Communications
Centillium Communications, Inc. is combining technical innovation and customer commitment to make broadband communications a market reality. Centillium consistently delivers value to its customers by providing broadband networking systems for applications across all market segments. The company designs and markets communications chipset solutions for central office equipment, digital loop carrier (DLC) line cards, and customer premise equipment for Digital Subscriber Line (DSL), Voice over Packet (VoP) and Premise Networking. The Centillium Communications headquarters are located at 47211 Lakeview Blvd., Fremont, CA 94538. Additional information is available at www.centillium.com.

Forward Looking Statements
Except for historical information contained in this press release, the foregoing contains forward-looking statements that involve risks and uncertainties. Actual results may differ materially from those indicated by such forward-looking statements based on a variety of risks and uncertainties, including the risks and uncertainties relating to actual quantities and timing of any orders received under the contract and the successful development and market acceptance of Centillium's new products. The company assumes no obligation to update these forward-looking statements to reflect events or circumstances after the date hereof. Information about potential factors that could affect Centillium's financial results is included in Centillium's Annual Report on Form 10-K and most recent Quarterly Report on Form 10-Q, available for viewing on the Securities and Exchange Commission's website at www.sec.gov.

Centillium Communications and the Centillium logo are trademarks of Centillium Communications.

Copyright 2003 Centillium Communications, Inc. All rights reserved. All other products or service names mentioned herein are the property of their respective owners.