RFC 2474 (rfc2474) - Page 1 of 20
Definition of the Differentiated Services Field (DS Field) in the IPv4 and IPv6 Headers
Alternative Format: Original Text Document
Network Working Group K. Nichols
Request for Comments: 2474 Cisco Systems
Obsoletes: 1455, 1349 S. Blake
Category: Standards Track Torrent Networking Technologies
F. Baker
Cisco Systems
D. Black
EMC Corporation
December 1998
Definition of the Differentiated Services Field (DS Field)
in the IPv4 and IPv6 Headers
Status of this Memo
This document specifies an Internet standards track protocol for the
Internet community, and requests discussion and suggestions for
improvements. Please refer to the current edition of the "Internet
Official Protocol Standards" (STD 1) for the standardization state
and status of this protocol. Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (1998). All Rights Reserved.
Abstract
Differentiated services enhancements to the Internet protocol are
intended to enable scalable service discrimination in the Internet
without the need for per-flow state and signaling at every hop. A
variety of services may be built from a small, well-defined set of
building blocks which are deployed in network nodes. The services
may be either end-to-end or intra-domain; they include both those
that can satisfy quantitative performance requirements (e.g., peak
bandwidth) and those based on relative performance (e.g., "class"
differentiation). Services can be constructed by a combination of:
- setting bits in an IP header field at network boundaries
(autonomous system boundaries, internal administrative boundaries,
or hosts),
- using those bits to determine how packets are forwarded by the
nodes inside the network, and
- conditioning the marked packets at network boundaries in accordance
with the requirements or rules of each service.
Nichols, et. al. Standards Track