The IESG has approved the following document: - 'Improving the Robustness of TCP to Non-Congestion Events ' <draft-ietf-tcpm-tcp-dcr-07.txt> as an Experimental RFC This document is the product of the TCP Maintenance and Minor Extensions Working Group. The IESG contact persons are Lars Eggert and Magnus Westerlund. A URL of this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-tcpm-tcp-dcr-07.txt Technical Summary This document specifies Non-Congestion Robustness (NCR) for TCP. One of the ways TCP detects loss is using the arrival of three duplicate acknowledgments. However, this heuristic is not always correct, notably in the case when network paths reorder segments. TCP-NCR is designed to mitigate this degraded performance by increasing the number of duplicate acknowledgments required to trigger loss recovery, based on the current state of the connection, in an effort to better disambiguate true segment loss from segment reordering. Working Group Summary This draft has attracted considerable interest in the WG, with many different people commenting on reviewing various iterations. The consensus was that although the specific benefits of the NCR extensions remain to be investigated, the mechanism itself is suitably ready for publication as an Experimental RFC. Protocol Quality PROTO Shepherd: Ted Faber (faber@isi.edu) The Gen-ART reviewer (Eric Gray, eric.gray@marconi.com) has found this ready for publication as an Experimental RFC. Chris Lonvick (clonvick@cisco.com) has reviewed this draft for the Security Directorate. Lars Eggert has reviewed this spec for the IESG. Note to RFC Editor Section 7, the only paragraph OLD: We do not believe there are security implications involved with TCP- NCR over and above those for general TCP congestion control [RFC2581]. In particular, the Extended Limited Transmit algorithms specified in this document have been specifically designed not to be susceptible to the sorts of ACK splitting attacks TCP's general TCP congestion control is vulnerable to (as discussed in [RFC3465]). NEW: General attacks against the congestion control of TCP are described in [RFC2581]. SACK-based loss recovery for TCP [RFC3517] mitigates some of the duplicate ACK attacks against TCP's congestion control. This document builds upon that work, and the Extended Limited Transmit algorithms specified in this document have been designed to thwart the ACK division problems that are described in [RFC3465]. (I.e., just replace the entire paragraph.) _______________________________________________ IETF-Announce@ietf.org https://www1.ietf.org/mailman/listinfo/ietf-announce
