gment of the overall storage markets about 10 percent." This statement was made publicly by EMC Corp. at its annual stockholders meeting on May 9, 2001. In a NAS, host computer systems use a file access protocol such as the Network File System (NFS). They access directories and files on storage devices. NAS-attached devices require and/or provide complete files or directories to interested and qualified parties. Unlike DAS, they do not just require raw blocks of bit data. NAS is clearly more sophisticated and efficient than DAS. Storage area network (SAN) This technology is experiencing phenomenal growth, according to multiple research analysts. For instance, in a July 2001 report called "Reweaving SAN Fabrics: Worldwide Open Systems SAN Interconnect Fabric Forecast and Analysis, 2001-2005," IDC pre- dicted that the SAN market will achieve an 80 percent cumulative annual growth rate (CAGR) by the end of 2004. SAN (which is reminiscent of a local area network [LAN]) is a generic name that describes a fully dedicated, reliable, and high-performance network that provides a direct connec- tion between servers and storage devices. Figure 11.1 illustrates this principle. Storage devices are not coupled to specific servers. Consequently, an entire organization can share resources since any computer system can be author- ized to access any storage device directly over the SAN. This freedom of scalable configuration and management, in addition to the technology's flexibility and reliability, has attracted the industry's attention. It has been shown to ultimately lead to lower costs of ownership. In this chapter, we will discuss a special breed of network processors intended to be used in SAN equipment. These network processors are already known in the industry by various names, such as storage coprocessors, storage processors, or SNPs. We will refer to them as SNPs to avoid confusion and capture their dual nature. More specifically, an SNP is a network processor that undisputedly spends time doing what all network process