This document describes how to set the Differentiated Services
Code Point (DSCP) values in Quality of Service (QoS)
configurations on a Cisco router, and it summarizes the
relationship between DSCP and IP precedence. You should be
familiar with the fields in the IP header and Cisco IOS® CLI
This document is not restricted to specific software and
hardware versions. The information presented in this document
was created from devices in a specific lab environment. All of
the devices used in this document started with a cleared
(default) configuration. If you are working in a live network,
ensure that you understand the potential impact of any command
before using it. Differentiated Services (DiffServ) is a new
model in which traffic is treated by intermediate systems with
relative priorities based on the type of services (ToS) field.
Defined in RFC 2474 and RFC 2475 , the DiffServ standard
supersedes the original specification for defining packet
priority described in RFC 791 . DiffServ increases the number of