xample, Douglas Comer, Internetworking with TCP/IP Vol.1: Principles, Protocols, and Architecture, 4th ed. (Upper Saddle River, New Jersey: Prentice-Hall, 2000), or Richard Stephens, Protocols (TCP/IP Illustrated Vol. 1) (Reading, Massachusetts: Addison-Wesley, 1994). 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. STORAGE NETWORK PROCESSORS (SNPS) 212 NETWORK PROCESSORS Fully terminates TCP in full-duplex Gigabit Ethernet, thereby offloading the host CPU. Natively supports multiple protocols such as iSCSI, NFS, and CIFS. Keeps upper-layer protocols (ULPs) fully aware of protocol data unit (PDU) content, placing incoming data directly into application buffers such as Fibre Channel. Fully maps the protocol onto the hardware, thereby achieving high throughput and low latency, which are two critical parameters that must be satisfied in order to be able to sustain wire-speed per- formance with the smallest possible I/O block sizes, as is the case with OLTP environments. The company has combined several technological advances to achieve the objectives. For instance, patent-pending technique of memory management eliminates the need to move the processed data around, which can significantly waste time. The management of multiple queues and two-tier classi- fication allow a class of service (CoS) approach to flow management for ordinary networking data traffic and iSCSI traffic. Hardware-assist units execute fixed functions such as performing integrity checks and running traffic statistics. Therefore, the iSNAP chip is designed to avoid things such as interrupts, memory access bottlenecks, and context switching overhead. As a result, net performance is maximized. Current iSNAP implementations can handle up to 50,000 TCP connections. In future designs, this technology is poised to scale to 10 Gbps storage network performance. Figure 11.7 illustrates 