{"draft":"draft-ietf-tcpm-tcp-lcd-03","doc_id":"RFC6069","title":"Making TCP More Robust to Long Connectivity Disruptions (TCP-LCD)","authors":["A. Zimmermann","A. Hannemann"],"format":["ASCII","HTML"],"page_count":"23","pub_status":"EXPERIMENTAL","status":"EXPERIMENTAL","source":"TCP Maintenance and Minor Extensions","abstract":"Disruptions in end-to-end path connectivity, which last longer than\r\none retransmission timeout, cause suboptimal TCP performance.  The\r\nreason for this performance degradation is that TCP interprets\r\nsegment loss induced by long connectivity disruptions as a sign of\r\ncongestion, resulting in repeated retransmission timer backoffs.\r\nThis, in turn, leads to a delayed detection of the re-establishment\r\nof the connection since TCP waits for the next retransmission timeout\r\nbefore it attempts a retransmission.\r\n\r\nThis document proposes an algorithm to make TCP more robust to long\r\nconnectivity disruptions (TCP-LCD).  It describes how standard ICMP\r\nmessages can be exploited during timeout-based loss recovery to\r\ndisambiguate true congestion loss from non-congestion loss caused by\r\nconnectivity disruptions.  Moreover, a reversion strategy of the\r\nretransmission timer is specified that enables a more prompt\r\ndetection of whether or not the connectivity to a previously\r\ndisconnected peer node has been restored.  TCP-LCD is a TCP sender-\r\nonly modification that effectively improves TCP performance in the\r\ncase of connectivity disruptions.  This document defines an Experimental \r\nProtocol for the Internet community.","pub_date":"December 2010","keywords":["Internet Control Message Protocol (ICMP)","Retranmission Timeout (RTO)"],"obsoletes":[],"obsoleted_by":[],"updates":[],"updated_by":[],"see_also":[],"doi":"10.17487\/RFC6069","errata_url":null}