From mboxrd@z Thu Jan 1 00:00:00 1970 From: raj ravi Subject: tcp_reordering as 0 possible? Date: Mon, 15 Mar 2010 19:55:16 +0530 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 To: netdev@vger.kernel.org Return-path: Received: from mail-vw0-f46.google.com ([209.85.212.46]:54475 "EHLO mail-vw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S936503Ab0COOZT (ORCPT ); Mon, 15 Mar 2010 10:25:19 -0400 Received: by vws12 with SMTP id 12so235481vws.19 for ; Mon, 15 Mar 2010 07:25:18 -0700 (PDT) Sender: netdev-owner@vger.kernel.org List-ID: Hi, what is the behaviour in TCP stack if I set tcp_reordering as 0. So , sender will start retransmission without waiting for any duplicate ACK ? /proc/sys/net/ipv4/tcp_reordering - Please clarify. The default value is 3 which means it waits until 3 duplicate ack's arrive and then start retransmission. "The TCP sender should use the fast retransmit algorithm to detect and repair loss based on incoming duplicate ACKs. After the arrival of 3 duplicate ACKs (4 identical ACKs without the arrival of any other intervening packet), TCP performs a retransmission of what appears to be the missing segment, without waiting for the retransmission timer to expire." Thanks! Kavi