ther it should be an integrated one or a standalone coprocessor that offloads the classification task from the network processor. Some products, especially search engines, require a search engine controller that supervises the operation of the search engine. This is rarely the network processor. In such cases, a separate proces- sor must be included in the board design. In an effort to differentiate their products, some vendors, such as NetLogic Microsystems, conve- niently call their products CFP processors, which is short for classification and forwarding proces- sors. These products usually combine a TCAM-based search engine implementing the LPM algorithm along with a programmable classification processor in one chip. The combination from a product- profile standpoint is a variation on a theme that fuses together what we discussed about search engines in the previous chapter with what we are discussing about classifiers here. To avoid sacrificing the generality of our treatment, we will not elaborate specifically on CFP processors. Other vendors, such as Raqia Networks, FastChip, and Solidum, propose standalone classification coprocessors, whose applicability is much wider than just switching and routing table lookup, as Downloaded from Digital Engineering Library @ McGraw-Hil (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. CLASSIFICATION PROCESSORS 252 NETWORK PROCESSORS Use of classification processors Virus scanning Intrusion Detection Firewall Load balancing PRODUCTIVE Use of CAM-based search engines Load balancing Network monitoring Quality of service Routing Switching Processing requirements (instructions per packet) FIGURE 13.7 The complexity of applications requiring classification determines the imple- mentation. (Source: Raqia Networks) shown in Figure 13.7. Their model and applicability is broad and interesting; therefore, it is worth- while that we review some of these approaches lat