/mcpQuality of Service for Voice over IP Resource Reservation Protocol 20 QoSVoIP.mif Precedence 5, which is the recommended ip precedence dial-peer configuration command setting for VoIP traffic. Therefore, if IP devices in the network can recognize IP Precedence or DSCP for classification and marking purposes, you can provision end-to-end QoS. DSCP Class-Based Marking Configuration Example The DS architecture specifies how to classify, mark, police, and shape traffic entering a DS region and how to treat different classes at every hop in the DS region. At the DS edge, all IP packets are marked with the appropriate DSCP so that QoS can be provided based on the DSCP inside the DS region. The following configuration example shows how to configure DSCP marking at the edge using class-based marking: All queueing and other QoS parameters now can be set to match on DSCP in the rest of the DS region. In the remaining sections of this document, we will match IP Precedence 5 traffic as VoIP and IP Precedence 3 traffic as HTTP (web traffic), with all other traffic going into the default class. Similarly, DSCP 46 could be used for VoIP and DSCP 26 for HTTP. We could use several other classification and marking mechanisms, but to maintain consistency and simplicity, we will use IP Precedence. Resource Reservation Protocol Resource Reservation Protocol (RSVP) is an implementation of the Integrated Services architecture for QoS (RFC 2205). When VoIP was introduced, RSVP was immediately seen as a key component that would provide admission control and QoS for VoIP flows. However, the way RSVP and H.323 were previously integrated provided neither admission control nor adequate QoS for voice flows. Several Configuration Example 9: Class-Based Marking of DSCP access-list 100 permit udp any any range 16384 32000 access-list 100 permit tcp any any eq 1720 access-list 101 permit tcp any any eq 80 ! class-map voip match access-group 100 class-map webtraffic match access-group 101 ! policy-map dscp_marking class voip set ip dscp 46 #EF Class class webtraffic set ip dscp 26 #AF Class ! interface Ethernet0/0 service-policy input dscp_marking In this example, all traffic coming in on Ethernet interface 0/0 is inspected and classified based on the voip and webtraffic class maps. The policy-map global configuration command sets the DSCP on the voip class traffic to 46 (101110 for EF) and the webtraffic class traffic to 26 (011010 for AF3).