elopment environments and support (also from third parties). As it continues to improve in performance with its second-generation processors, Intel is clearly setting its sights on the faster, more lucrative edge and core equipment markets. INTEL IXA: THE BIG PICTURE Intel IXA is an end-to-end family of high-performance, flexible, and scalable hardware and software development building blocks that have been designed to satisfy the growing performance require- ments in today's networks. The architecture is based on programmable silicon and software building blocks. At the low end of its offering, Intel has positioned its IXP220, 225, and 425 NPUs as integrated solutions that are suited for small officelhome office (SOHO) and small medium enterprise (SME) equipment in a CPE premise. However, the cornerstone of Intel's IXA family is the IXP1200 network processor and its variants IXP1240, 1250, and SO on. These NPUs run at different clock frequencies and with or without added features such as embedded cyclic redundancy check (CRC) and error cor- rection code (ECC) memory access. On top of the 1200 family, Intel has recently brought a couple of powerful additions into the market. For the OC-12 to OC-48 (2.5 Gbps) realms, Intel introduced the IXP2400 in 2002. For the OC-48 to OC-192 (10 Gbps) realms, Intel's flagship NPU is the IXP2800 network processor. Unlike IBM, Intel does not yet offer switch fabrics; therefore, standard interfaces must be provided to connect to fabrics provided by other vendors. Intel's first-generation NPUs were already designed to enable the high-speed manipulation of packets across several media types and forward packets effi- ciently with the appropriate modification of packet headers while reserving sufficient compute cycles Downloaded from Digital Engineering Library @ McGraw-Hill (www.digitalengineeringlibrary.com) Copyright © 2004 The McGraw-Hill Companies. All rights reserved. Any use is subject to the Terms of Use as given at the website. INTEL IXATM NETWORK PROCESSORS 78 NETWORK PROCES