{"id":423,"date":"2010-02-28T21:07:21","date_gmt":"2010-02-28T20:07:21","guid":{"rendered":"http:\/\/ccievoice.ksiazek.be\/?p=423"},"modified":"2025-01-11T18:28:05","modified_gmt":"2025-01-11T17:28:05","slug":"weighted-random-early-detection-wred","status":"publish","type":"post","link":"https:\/\/collaboration.ksiazek.be\/?p=423","title":{"rendered":"Weighted Random Early Detection &#8211; WRED"},"content":{"rendered":"<p>Whereas queuing provides congestion management, mechanisms such as WRED provide <span style=\"text-decoration: underline;\"><em>congestion avoidance<\/em><\/span>.WRED&#8217;s purpose is to prevent an output queue from ever filling to capacity,which would result in packet loss for incoming packets.<\/p>\n<p>To understand what it is WRED ,let&#8217;s explain first RED goals, basics<\/p>\n<p>The purposes of RED is to prevent TCP synchronization (all TCP streams in slow start phase) by randomly discarding packets as an interface&#8217;s output queue begins to fill.<\/p>\n<p>The agressivity of discarding packets depends on the queue depth and is influenced by the minimum , the maximum threshold and the Mark Probability Denominator(MPD).<\/p>\n<p>So random dropping will happen when you reaches the minimum threshold and it is full when you reach the maximum threshold .<\/p>\n<p><a href=\"http:\/\/alnpcruz.preview.infomaniak.com\/wp-content\/uploads\/2010\/03\/Red-Dropping.png\"><img loading=\"lazy\" decoding=\"async\" class=\"aligncenter size-full wp-image-427\" title=\"Red Dropping\" src=\"http:\/\/alnpcruz.preview.infomaniak.com\/wp-content\/uploads\/2010\/03\/Red-Dropping.png\" alt=\"Explanation of RED\" width=\"594\" height=\"338\" srcset=\"https:\/\/collaboration.ksiazek.be\/wp-content\/uploads\/2010\/03\/Red-Dropping.png 594w, https:\/\/collaboration.ksiazek.be\/wp-content\/uploads\/2010\/03\/Red-Dropping-300x171.png 300w\" sizes=\"(max-width: 594px) 100vw, 594px\" \/><\/a><\/p>\n<p>Another definition for the MPD is the maximum drop percentage at the maximum threshold.<\/p>\n<p>RED is not supported on Cisco IOS but Cisco has chosen to support CB-WRED which gives you the opportunity to define several RED mechanisms for different DSCP threshold.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>Whereas queuing provides congestion management, mechanisms such as WRED provide congestion avoidance.WRED&#8217;s purpose is to prevent an output queue from ever filling to capacity,which would result in packet loss for incoming packets. To understand what it is WRED ,let&#8217;s explain first RED goals, basics The purposes of RED is to prevent TCP synchronization (all TCP [&hellip;]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_et_pb_use_builder":"","_et_pb_old_content":"","_et_gb_content_width":"","footnotes":""},"categories":[30,1,80,33],"tags":[59,81,136],"class_list":["post-423","post","type-post","status-publish","format-standard","hentry","category-ios","category-non-classe","category-qos","category-written-theory","tag-ccie-voice-written","tag-qos","tag-wred"],"_links":{"self":[{"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=\/wp\/v2\/posts\/423","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=423"}],"version-history":[{"count":1,"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=\/wp\/v2\/posts\/423\/revisions"}],"predecessor-version":[{"id":4456,"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=\/wp\/v2\/posts\/423\/revisions\/4456"}],"wp:attachment":[{"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=423"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=423"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/collaboration.ksiazek.be\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=423"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}