Making TCP More Robust to Long Connectivity Disruptions (TCP-LCD)
RFC 6069

Approval announcement
Draft of message to be sent after approval:

From: The IESG <>
To: IETF-Announce <>
Cc: Internet Architecture Board <>,
    RFC Editor <>,
    tcpm mailing list <>,
    tcpm chair <>
Subject: Document Action: 'Making TCP more Robust to Long Connectivity Disruptions (TCP-LCD)' to Experimental RFC

The IESG has approved the following document:
- 'Making TCP more Robust to Long Connectivity Disruptions (TCP-LCD)'
  <draft-ietf-tcpm-tcp-lcd-03.txt> as an Experimental RFC

This document is the product of the TCP Maintenance and Minor Extensions
Working Group.

The IESG contact person is Lars Eggert.

A URL of this Internet Draft is:

Technical Summary

  Disruptions in end-to-end path connectivity, which last longer than
  one retransmission timeout, cause suboptimal TCP performance.
  This document proposes an algorithm to make TCP more robust to long
  connectivity disruptions (TCP-LCD).  It describes how standard ICMP
  messages can be exploited during timeout-based loss recovery to
  disambiguate true congestion loss from non-congestion loss caused by
  connectivity disruptions.

Working Group Summary 

  Nothing exceptional occurred during the working group process for this

Document Quality 

  There is an existing implementation in Linux, which was worked on by
  the document authors.  This has been in the vanilla kernel since version
  2.6.32 (for about a year) and always enabled.  Several Linux distributions
  have shipped with this and no negative experiences have been reported that
  were isolated to this mechanism.


  Wesley Eddy ( is the document shepherd. Lars
  Eggert ( has reviewed this document for the IESG.