Subject: WG Review: Revised Charter for Differentiated Services (diffserv)

From: The IESG <[email-masked]>
Date: Fri, 22 Jan 1999 15:43:57 -0500

A revised charter has been received for the Differentiated Services
(diffserv) Working Group, and is provided here for informational
purposes.

The current charter can be accessed at: 

	http://www.ietf.org/html.charters/diffserv-charter.html
=======

Description of Working Group:

There is a clear need for relatively simple and coarse
methods of providing differentiated classes of service for
Internet traffic, to support various types of applications,
and specific business requirements. The differentiated services approach to
providing quality of service in networks employs a small, well-
defined set of building blocks from which a variety of services may
be built. A small bit-pattern in each packet, in the IPv4 TOS octet or the
IPv6 Traffic Class octet, is used to mark a packet to receive a particular
forwarding treatment, or per-hop behavior, at each network node. A common
understanding about the use and interpretation of this bit-pattern is
required for inter-domain use, multi-vendor interoperability, and
consistent reasoning about expected service behaviors in a network. Thus,
the Working Group has standardized a common layout to be used for both
octets, called the 'DS field'. RFC 2474 and RFC 2475 define the
architecture, and the general use of bits within the DS field (superseding
the IPv4 TOS octet definitions of RFC 1349). The Working Group will also
standardize a small number of specific per-hop behaviors,
and recommend a particular bit pattern or 'code-point'
of the DS field for each one. 

In addition, an informational framework document will be produced.
The framework document will describe more general aspects of the
differentiated services environment. It will give general examples
and possible services representing our current understanding. Since
the services and signalling architectures are expected to undergo the
most evolution as diffserv is deployed, this document will capture
current understanding only.

Another goal of the WG is to allow experiments with other per-hop
behaviors that can be used to produce additional services. These will be
documented in Internet Drafts. It will be decided whether these additional
per-hop behaviors should be specified in experimental RFCs or should become
standardized. The WG will also investigate the additional components
necessary to support differentiated services, including such traffic
conditioners as traffic shapers and packet markers that could be used at
the boundaries of networks. In particular, the WG will define a general
conceptual model for boundary devices, including traffic conditioning
parameters, and configuration and monitoring data. It is expected
that a subset of this will apply to all diffserv nodes. The group
will also define a MIB for diffserv nodes.

The group will analyze related security threats, especially theft
of service or denial of service attacks, and suggest counter-measures.

The group will not work on
 -mechanisms for the identification of individual traffic flows
 -new signalling mechanisms to support the marking of packets
 -end to end service definitions
 -service level agreements

Goals and Milestones:

Jan 99: Finalize EF per hop behaviour draft, submit to IESG

Feb 99: Publish boundary device model and MIB drafts
        Finalize AF per hop behaviour draft, submit to IESG

Mar 99: Meet at Minneapolis IETF to finalize framework draft and discuss
        boundary draft and MIB draft

May 99: Finalize boundary and MIB drafts, submit to IESG

Jul 99: Meet at Oslo IETF to review any open issues.