RFC 3708 (rfc3708) - Page 1 of 9
Using TCP Duplicate Selective Acknowledgement (DSACKs) and Stream Control Transmission Protocol (SCTP) Duplicate Transmission Sequence Numbers (TSNs) to Detect Spurious Retransmissions
Alternative Format: Original Text Document
Network Working Group E. Blanton
Request for Comments: 3708 Purdue University
Category: Experimental M. Allman
ICIR
February 2004
Using TCP Duplicate Selective Acknowledgement (DSACKs) and
Stream Control Transmission Protocol (SCTP) Duplicate
Transmission Sequence Numbers (TSNs) to Detect Spurious
Retransmissions
Status of this Memo
This memo defines an Experimental Protocol for the Internet
community. It does not specify an Internet standard of any kind.
Discussion and suggestions for improvement are requested.
Distribution of this memo is unlimited.
Copyright Notice
Copyright (C) The Internet Society (2004). All Rights Reserved.
Abstract
TCP and Stream Control Transmission Protocol (SCTP) provide
notification of duplicate segment receipt through Duplicate Selective
Acknowledgement (DSACKs) and Duplicate Transmission Sequence Number
(TSN) notification, respectively. This document presents
conservative methods of using this information to identify
unnecessary retransmissions for various applications.
1. Introduction
TCP [RFC 793] and SCTP [RFC 2960] provide notification of duplicate
segment receipt through duplicate selective acknowledgment (DSACK)
[RFC 2883] and Duplicate TSN notifications, respectively. Using this
information, a TCP or SCTP sender can generally determine when a
retransmission was sent in error. This document presents two methods
for using duplicate notifications. The first method is simple and
can be used for accounting applications. The second method is a
conservative algorithm to disambiguate unnecessary retransmissions
from loss events for the purpose of undoing unnecessary congestion
control changes.
Blanton & Allman Experimental