rv The Integrated Services (IntServ) protocol (RFC 1633) is structured upon a framework that uses four fundamental components: A signaling protocol, which requests that specific network resources be reserved downstream in anticipation of transmission. An admission control scheme that will decide whether the requested resources will be reserved as requested. 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. TRAFFIC MANAGERS NETWORK PROCESSORS A multifield-based classifier. A scheduler that will handle a packet as needed in order for it to obtain the necessary QoS. For signaling purposes, IntServ uses RSVP (RFC 2210) extensively, As mentioned previously, this requires that flow-related state information also be kept in intermediate nodes, not just in end systems. In conjunction with the following three classes of traffic that IntServ defines, it essentially behaves as a connection-oriented protocol that is similar to ATM switching. Packet flows are assigned to one of three classes defined in IntServ: Guaranteed service, which is used for applications that need assurances for no packet loss and controlled/specified latency bounds. Predictive service (also known as controlled-load service), which is used for applications that require probabilistic delay bounds, a realm where the presence of either light or heavy traffic on the network will not affect this class of traffic. Best-efforts service. In order for this approach to function, specific resources need to be reserved from the network in anticipation of the needs of individual packet streams or flows. Consequently, routers must retain flow-related state information. The guaranteed service requires that all routers be capable of IntServ, which did not materialize as a vision. The predictive service, however, could work in principle if it was configured in conjunction with RSVP as its signaling 