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SACK-IMMEDIATELY Extension for the Stream Control Transmission Protocol
RFC 7053

Approval announcement
Draft of message to be sent after approval:


From: The IESG <>
To: IETF-Announce <>
Cc: RFC Editor <>
Subject: Protocol Action: 'SACK-IMMEDIATELY Extension for the Stream Control Transmission Protocol' to Proposed Standard (draft-ietf-tsvwg-sctp-sack-immediately-04.txt)

The IESG has approved the following document:
- 'SACK-IMMEDIATELY Extension for the Stream Control Transmission
  (draft-ietf-tsvwg-sctp-sack-immediately-04.txt) as Proposed Standard

This document is the product of the Transport Area Working Group.

The IESG contact persons are Spencer Dawkins and Martin Stiemerling.

A URL of this Internet Draft is:

Ballot Text

Technical Summary

This document updates RFC 4960 by defining a method for the sender of
a DATA chunk to indicate that the corresponding SACK chunk should be
sent back immediately and not be delayed. It is done by specifying a
bit in the DATA chunk header, called the I-bit, which can get set
either by the SCTP implementation or by the application using an SCTP
stack. Since unknown flags in chunk headers are ignored by SCTP
implementations, this extension does not introduce any
interoperability problems.

Working Group Summary

There was consensus to adopt this as a WG document, review by the WG,
and agreement by the WG to finally publish this.

Document Quality

This document is seen as ready to publish.

FreeBSD supports this extension since FreeBSD 7.2, released May 2009.
The Linux kernel supports it also (accessibility by the user was added
recently to netinet/sctp.h).


The document shepherd is: Gorry Fairhurst, <>.
The responsible AD is: Spencer Dawkins <>

RFC Editor Note