TCP and Stream Control Transmission Protocol (SCTP) RTO Restart
RFC 7765
Document | Type | RFC - Experimental (February 2016; No errata) | |
---|---|---|---|
Authors | Per Hurtig , Anna Brunstrom , Andreas Petlund , Michael Welzl | ||
Last updated | 2016-02-11 | ||
Replaces | draft-hurtig-tcpm-rtorestart | ||
Stream | Internent Engineering Task Force (IETF) | ||
Formats | plain text html pdf htmlized (tools) htmlized bibtex | ||
Reviews | |||
Stream | WG state | Submitted to IESG for Publication | |
Document shepherd | Michael Scharf | ||
Shepherd write-up | Show (last changed 2015-07-20) | ||
IESG | IESG state | RFC 7765 (Experimental) | |
Action Holders |
(None)
|
||
Consensus Boilerplate | Yes | ||
Telechat date | |||
Responsible AD | Martin Stiemerling | ||
Send notices to | (None) | ||
IANA | IANA review state | Version Changed - Review Needed | |
IANA action state | No IANA Actions |
Internet Engineering Task Force (IETF) P. Hurtig Request for Comments: 7765 A. Brunstrom Category: Experimental Karlstad University ISSN: 2070-1721 A. Petlund Simula Research Laboratory AS M. Welzl University of Oslo February 2016 TCP and Stream Control Transmission Protocol (SCTP) RTO Restart Abstract This document describes a modified sender-side algorithm for managing the TCP and Stream Control Transmission Protocol (SCTP) retransmission timers that provides faster loss recovery when there is a small amount of outstanding data for a connection. The modification, RTO Restart (RTOR), allows the transport to restart its retransmission timer using a smaller timeout duration, so that the effective retransmission timeout (RTO) becomes more aggressive in situations where fast retransmit cannot be used. This enables faster loss detection and recovery for connections that are short lived or application limited. Status of This Memo This document is not an Internet Standards Track specification; it is published for examination, experimental implementation, and evaluation. This document defines an Experimental Protocol for the Internet community. This document is a product of the Internet Engineering Task Force (IETF). It represents the consensus of the IETF community. It has received public review and has been approved for publication by the Internet Engineering Steering Group (IESG). Not all documents approved by the IESG are a candidate for any level of Internet Standard; see Section 2 of RFC 5741. Information about the current status of this document, any errata, and how to provide feedback on it may be obtained at http://www.rfc-editor.org/info/rfc7765. Hurtig, et al. Experimental [Page 1] RFC 7765 TCP and SCTP RTO Restart February 2016 Copyright Notice Copyright (c) 2016 IETF Trust and the persons identified as the document authors. All rights reserved. This document is subject to BCP 78 and the IETF Trust's Legal Provisions Relating to IETF Documents (http://trustee.ietf.org/license-info) in effect on the date of publication of this document. Please review these documents carefully, as they describe your rights and restrictions with respect to this document. Code Components extracted from this document must include Simplified BSD License text as described in Section 4.e of the Trust Legal Provisions and are provided without warranty as described in the Simplified BSD License. Table of Contents 1. Introduction . . . . . . . . . . . . . . . . . . . . . . . . 3 2. Terminology . . . . . . . . . . . . . . . . . . . . . . . . . 4 3. RTO Overview and Rationale for RTOR . . . . . . . . . . . . . 4 4. RTOR Algorithm . . . . . . . . . . . . . . . . . . . . . . . 6 5. Discussion . . . . . . . . . . . . . . . . . . . . . . . . . 7 5.1. Applicability . . . . . . . . . . . . . . . . . . . . . . 7 5.2. Spurious Timeouts . . . . . . . . . . . . . . . . . . . . 7 5.3. Tracking Outstanding and Previously Unsent Segments . . . 8 6. Related Work . . . . . . . . . . . . . . . . . . . . . . . . 9 7. SCTP Socket API Considerations . . . . . . . . . . . . . . . 10 7.1. Data Types . . . . . . . . . . . . . . . . . . . . . . . 10 7.2. Socket Option for Controlling the RTO Restart Support (SCTP_RTO_RESTART) . . . . . . . . . . . . . . . . . . . 10 8. Security Considerations . . . . . . . . . . . . . . . . . . . 11 9. References . . . . . . . . . . . . . . . . . . . . . . . . . 11 9.1. Normative References . . . . . . . . . . . . . . . . . . 11 9.2. Informative References . . . . . . . . . . . . . . . . . 13 Acknowledgements . . . . . . . . . . . . . . . . . . . . . . . . 14 Authors' Addresses . . . . . . . . . . . . . . . . . . . . . . . 15 Hurtig, et al. Experimental [Page 2] RFC 7765 TCP and SCTP RTO Restart February 2016 1. Introduction TCP and SCTP use two almost identical mechanisms to detect and recover from data loss, specified in [RFC6298] and [RFC5681] for TCP and [RFC4960] for SCTP. First, if transmitted data is not acknowledged within a certain amount of time, a retransmission timeout (RTO) occurs and the data is retransmitted. While the RTO is based on measured round-trip times (RTTs) between the sender and receiver, it also has a conservative lower bound of 1 second toShow full document text