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RACK: a time-based fast loss detection algorithm for TCP

The information below is for an old version of the document.
Document Type This is an older version of an Internet-Draft whose latest revision is Replaced
Authors Yuchung Cheng , Neal Cardwell
Last updated 2016-04-21 (Latest revision 2015-10-19)
Replaced by draft-ietf-tcpm-rack, draft-ietf-tcpm-rack, draft-ietf-tcpm-rack, RFC 8985
Stream (None)
Expired & archived
Stream Stream state (No stream defined)
Consensus boilerplate Unknown
RFC Editor Note (None)
IESG IESG state Expired
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This Internet-Draft is no longer active. A copy of the expired Internet-Draft is available in these formats:


This document presents a new TCP loss detection algorithm called RACK ("Recent ACKnowledgment"). RACK uses the notion of time, instead of packet or sequence counts, to detect losses, for modern TCP implementations that can support per-packet timestamps and the selective acknowledgment (SACK) option. It is intended to replace the conventional DUPACK threshold approach and its variants, as well as other nonstandard approaches.


Yuchung Cheng
Neal Cardwell

(Note: The e-mail addresses provided for the authors of this Internet-Draft may no longer be valid.)