Skip to main content

Integrated Services over Specific Link Layers

Document Charter Integrated Services over Specific Link Layers WG (issll)
Title Integrated Services over Specific Link Layers
Last updated 2002-05-13
State Approved
WG State Concluded
IESG Responsible AD (None)
Charter edit AD (None)
Send notices to (None)


The ISSLL Working Group defines specifications and techniques needed
to implement Internet Integrated Services capabilities within specific
network technologies.

The Internet Integrated Services design, developed within the IETF by
working groups such as INTSERV and RSVP, specifies extensions to the
IP architecture which allow applications to request and receive a
specific level of service from the internetwork, as alternatives to
the current IP best-effort service class. The work of these groups has
resulted in technology-independent protocols and specifications.
Focused engineering work to define the mapping of these universal
specifications onto specific subnetwork technologies is now required.

At minimum, the following points must be addressed for each candidate

  • Service mappings. Service mappings define the way that the link layer
    technology is used to provide a particular IntServ traffic management
    service, such as controlled-load or guaranteed-delay.

  • Setup protocol mappings. Setup protocol mappings define how an
    level setup protocol such as RSVP is implemented or mapped onto the
    layer technology.

  • Adaptation protocols. Adaptation protocols are used to augment the
    native capabilities of the link-layer technology, when this is
    necessary to support required Integrated Services functions.

  • Statements of non-applicability. Statements of non-applicability
    which Integrated Service capabilities are not supported by the link
    layer technology under consideration.

The ISSLL WG will carry out this work for all technologies with
market demand and of sufficient interest to its members. To ensure
progress on each work item the WG will employ an administrative
based on technology coordinators, as described below. The WG expects to
coordinate its activities across technologies whenever technical
commonality between layer two media is apparent. The WG chairs hold
primary responsibility for this coordinating role.

WG Outputs:

The WG is expected to produce standards-track RFC's, informational RFC's
and "best-current-practices" guidelines, as required. The need for
standards-track RFC's is limited both because the work of the group is
focused on the engineering of existing protocols to existing link layer
technologies, and because in certain cases information and guidelines
will better serve the needs of a rapidly evolving technology.

Operational Structure:

Due to the scope of the task and the need for parallel progress on
multiple work items, the WG effort is organized as follows:

A technical coordinator will be identified and selected for each media
technology adopted as a work item by the group. This person will be
responsible for coordinating the technical efforts of the group with
respect to that media, working with and motivating the document
editors, and evangelizing the group's work within the community and
relevant external organizations such as the IEEE and ATM Forum.

Since many link layer media continue to evolve, and since that evolution
may be influenced by the work of the ISSLL WG, it is expected that each
technology work item will be divided into short term tasks, medium term
tasks, and ongoing monitoring, as follows:

  • Short term tasks focus on using the existing technology as best
    as possible with no changes whatsoever. This work will accept whatever
    limits are imposed the link-level and IP-level technology, with the
    goal of creating the best solution possible within a 6-9 month

  • Medium term tasks focus on planned changes to the technology that are
    currently being standardized and may not yet be widely available
    Ideally this work would conclude just as the changes become available
    in the market. In general a 1-1.5 year timeframe is appropriate for

  • Monitoring focuses on tracking and advising on changes being made by
    others to a link layer technology, to allow it to better support the
    Integrated Services models and protocols. Generally, these efforts
    be conducted as informal activities, rather than work items within the
    structure. The exception would be when formal cooperation between the
    and an external effort was required.

In addition to the normal responsibilities of IETF working group chairs,
the ISSLL chairs hold primary responsibility for selection of
identifying areas of technical commonality and building cross-technology
efforts within the group.

Relationship to Other Working Groups:

The ISSLL WG maintains a close working relationship with the INTSERV
and RSVP WG's. Particularly, ISSLL may wish to feed back information
about the effectiveness or limitations of RSVP and INTSERV work in the
context of a specific technology to these groups for review. ISSLL is
also expected to interact with other WG's as needed to aid in the use
of particular media (e.g. IPATM, PPPEXT).

Coordinators for initially important technologies:

ATM Sue Thomson,
Low-Speed Serial Carsten Bormann,
Token Ring Wayne Pace,
Frame Relay
Cable Modems