Integrated Services (intserv)
|Area:||Transport Area (tsv)|
John Wroclawski <email@example.com>
Recent experiments demonstrate the capability of packet switching
protocols to support Integrated Services --- the transport of audio,
video, real-time, and classical data traffic within a single network
infrastructure. These experiments suggest that expanding the Internet
service model would better meet the needs of these diverse applications.
The purpose of this working group is to specify this enhanced service
model and then to define and standardize certain interfaces and
requirements necessary to implement the new service model.
The working group will focus on defining a minimal set of global
requirements which transition the Internet into a robust
integrated-service communications infrastructure. Enhancements to
individual protocols (e.g., adding additional routing information to
routing protocols, or choosing IP queueing disciplines for routers)
will be left to other working groups, except in those rare cases where
detailed definitions of behavior are critical to the success of the
Extending the Internet service model raises a series of questions.
The working group will focus on the three problems listed below:
(1) Clearly defining the services to be provided. The first task
faced by this working group is to define and document the enhanced
Internet service model.
(2) Defining the application service, router scheduling and (general)
subnet interfaces. The working group must define at least three
high-level interfaces: that expressing the application's end-to-end
requirements, that defining what information is made available to
individual routers within the network, and the additional
expectations (if any) the enhanced service model has for subnet
technologies. The working group will define these abstract
interfaces, and will coordinate with and advise IP over "subnet"
working groups (such as IP over ATM) in this.
(3) Developing router validation requirements which can ensure that
the proper service is provided. We assume that the Internet will
continue to contain a heterogeneous set of routers, running
different routing protocols and using different forwarding
algorithms. The working group will seek to define a minimal set of
additional router requirements which ensure that the Internet can
support the new service model. Rather than presenting specific
scheduling and admission control algorithms which must be supported,
these requirements will likely take the form of behavioral tests
which measure the capabilities of routers in the integrated
services environment. This approach is used because no single
algorithm seems likely to be appropriate in all circumstances at
This time. The working group will coordinate with the Benchmarking
Working Group (BMWG).
We expect to generate three RFCs as a product of performing these tasks.
An important aspect of this working group's charter is in coordination
with the development of IP Next Generation. The working group will
be reviewed in November 1995 to determine if it should be re-chartered
as is or modified to reflect IPng developments, in particular, but also
operational and commercial developments. The IESG deems the great
significance of this working group to merit this unusual review.
In addition, because many of the integrated services concepts are new,
the working group may produce Informational RFCs explaining specific
algorithms that may be appropriate in certain circumstances, and may
host some educational meetings to assist both IETF members and members
of the larger Internet community to understand the proposed enhancements
The working group proposes to hold regular meetings beyond those held at
the IETF meetings.
Seattle IETF: First full meeting of working group. Discuss proposed service model. Discuss strategy for addressing other issues.
Submit Informational RFC on service model. Discuss initial draft documents describing router requirements and strategies for behavioral testing. Hold coordination meeting with RSVP Working Group (and perhaps others as well) to discuss Application (end-to-end) PI.
Continue discussion of router requirements. Develop experimental verification of behavioural testing approach. Continue discussion of API and subnet models.
Submit API. Working group charter will be revised after a working group review managed by the area director, then submitted via the normal chartering process for approval.
Submit router requirements document for publication as an RFC.
Submit subnet document for publication as an RFC.
Submit draft on encoding of flow compression information within IntServ Flow Specification for publication as Standards-track RFC