{"id":1612,"date":"2010-06-05T16:20:51","date_gmt":"2010-06-05T10:50:51","guid":{"rendered":"http:\/\/www.jeffrin.in\/?p=1612"},"modified":"2010-06-05T16:20:51","modified_gmt":"2010-06-05T10:50:51","slug":"f-rto-response","status":"publish","type":"post","link":"https:\/\/www.trueangle.org\/index.php\/2010\/06\/05\/f-rto-response\/","title":{"rendered":"F-RTO  response"},"content":{"rendered":"<pre>\n$cat \/proc\/sys\/net\/ipv4\/tcp_frto_response\n0\n$\n<\/pre>\n<pre>\nWhen F-RTO has detected that a TCP retransmission timeout was spurious (i.e, the timeout would have been avoided had TCP set a\nlonger retransmission timeout), TCP has several options what to do\nnext. Possible values are:\n\n0 Rate halving based; a smooth and conservative response,\nresults in halved cwnd and ssthresh after one RTT\n\n1 Very conservative response; not recommended because even\nthough being valid, it interacts poorly with the rest of\nLinux TCP, halves cwnd and ssthresh immediately\n\n2 Aggressive response; undoes congestion control measures\nthat are now known to be unnecessary (ignoring the\npossibility of a lost retransmission that would require\nTCP to be more cautious), cwnd and ssthresh are restored\nto the values prior timeout\n\nDefault: 0 (rate halving based)\n\nsource : Linux kernel source documentation.\n<\/pre>\n<pre>\nSlow-start threshold (ssthresh) state variable is used to determine\n\nwhether the slow-start or congestion avoidance algorithm is used to\n\ncontrol data transmission.\n\nsource : http:\/\/www.opalsoft.net\/qos\/TCP-1010.htm\n<\/pre>\n<pre>\n\nqw_tools\/System.map\n 25124: c03764a0 D sysctl_tcp_ecn\n 25125: c03764a4 D sysctl_tcp_frto_response\n 25126: c03764a8 D sysctl_tcp_nometrics_save\ngithub.com\/vjosech\/QemuWatcher.git - Unknown\n\ncode\/ns-2\/?raw-diff\/1056ff50e303\/tcp\/tcp.h\n   445: +       \/* for experimental high-speed TCP *\/\n   446: +       \/* These four parameters define the HighSpeed response function. *\/\n   447: +       int low_window_;        \/* window for turning on high-speed TCP *\/\n   448: +       int high_window_;       \/* target window for new response function *\/\n   449: +       double high_p_;         \/* target drop rate for new response function *\/\nyans.inria.fr\/code\/ns-2\/?raw-diff\/1056ff50e303\/tcp\/tcp.h - BSD - C++ -\n<\/pre>\n<pre>\nResearch Paper.\n\n<a href=\"http:\/\/www.jeffrin.in\/wp-content\/uploads\/2010\/06\/2008_Enhanced-Response-Algorithm-for-Spurious-TCP.pdf\">http:\/\/www.jeffrin.in\/wp-content\/uploads\/2010\/06\/2008_Enhanced-Response-Algorithm-for-Spurious-TCP.pdf<\/a>\n<\/pre>\n","protected":false},"excerpt":{"rendered":"<p>$cat \/proc\/sys\/net\/ipv4\/tcp_frto_response 0 $ When F-RTO has detected that a TCP retransmission timeout was spurious (i.e, the timeout would have been avoided had TCP set a longer retransmission timeout), TCP has several options what to do next. Possible values are: 0 Rate halving based; a smooth and conservative response, results in halved cwnd and ssthresh &hellip; <\/p>\n<p class=\"link-more\"><a href=\"https:\/\/www.trueangle.org\/index.php\/2010\/06\/05\/f-rto-response\/\" class=\"more-link\">Continue reading<span class=\"screen-reader-text\"> &#8220;F-RTO  response&#8221;<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":[],"categories":[1],"tags":[1055],"_links":{"self":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/1612"}],"collection":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/comments?post=1612"}],"version-history":[{"count":0,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/posts\/1612\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/media?parent=1612"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/categories?post=1612"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.trueangle.org\/index.php\/wp-json\/wp\/v2\/tags?post=1612"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}