Subject: WG Review: Datagram Congestion Control Protocol (dccp)

From: Steve Coya <[email-masked]>
Date: Mon, 17 Jun 2002 12:01:33 -0400

A new IETF working group has been proposed in the Transport Area.
The IESG has not made any determination as yet. 

The following Description was submitted, and is provided for
informational purposes only:

Datagram Congestion Control Protocol (dccp)
-------------------------------------------

 Current Status: Proposed Working Group

Description of Working Group:

The Datagram Control Protocol working group is chartered to develop and
standardize the Datagram Congestion Control Protocol (DCCP). DCCP is a
minimal general purpose transport-layer protocol providing only two
core functions:

- the establishment, maintenance and teardown of an unreliable packet
  flow.

- congestion control of that packet flow.

Within the constraints of providing these core functions, DCCP aims to 
be a general purpose protocol, minimizing the overhead of packet header 
size or end-node processing as much as possible. Therefore, DCCP is as 
simple as possible, and as far as reasonably possible, it should avoid 
providing higher-level transport functionality. DCCP will provide a
congestion-controlled, unreliable packet stream, without TCP's 
reliability or in-order delivery semantics. Additional unicast, 
flow-based application functionality can be layered over DCCP.

SCOPE

Drafts for DCCP, and several associated congestion control IDs, already
exist. The first task before the working group will be an abbreviated
functional requirement validation of those drafts. There are two 
possible outcomes:

1. The current DCCP draft is declared suitable for further work, with 
   some areas listed for possible extension.

2. The current DCCP draft is declared unsuitable for further work, and
   more formal functional requirement exploration begins.

Prior to the final development of the protocol, the working group will
investigate areas of functionality that should be integrated into DCCP
because they are difficult or impossible to layer above it. These areas
include security and multi-homing/mobility, at a minimum. The protocol
will be for both IPv4 and IPv6. It will not encompass multicast. It
is strictly a unicast transport.

For security, the working group will endeavor to ensure that DCCP
incorporates good non-cryptographic mechanisms that make it resistant
to denial-of-service attacks on DCCP connections and DCCP servers. A 
related topic that will be explored is whether DCCP can be a candidate 
to replace UDP in the transport of security management protocols such
as IKE and JFK.

The working group will also investigate DCCP's relationship with RTP 
(the Real-time Transport Protocol).

Once the DCCP specification has stabilized, the WG will produce a 
document providing guidance to potential users of DCCP. The precise form 
of this document will be determined by WG discussion, but it might 
include example APIs, an applicability statement, or other forms of 
guidance about appropriate usage of DCCP.