From owner-freebsd-net@FreeBSD.ORG Tue Sep 11 23:41:43 2007 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 2883416A417 for ; Tue, 11 Sep 2007 23:41:43 +0000 (UTC) (envelope-from nataraja@cis.udel.edu) Received: from mail.eecis.udel.edu (louie.udel.edu [128.4.40.12]) by mx1.freebsd.org (Postfix) with ESMTP id F16A913C49D for ; Tue, 11 Sep 2007 23:41:42 +0000 (UTC) (envelope-from nataraja@cis.udel.edu) Received: by mail.eecis.udel.edu (Postfix, from userid 62) id 038B12E1E; Tue, 11 Sep 2007 19:12:57 -0400 (EDT) X-Spam-Checker-Version: SpamAssassin 3.1.8 (2007-02-13) on louie.udel.edu X-Spam-Level: X-Spam-Status: No, score=-22.1 required=4.1 tests=ALL_TRUSTED,AWL,BAYES_00, LOCAL_AUTH_RCVD autolearn=unavailable version=3.1.8 Received: from [192.168.1.102] (c-68-37-2-210.hsd1.de.comcast.net [68.37.2.210]) (Authenticated sender: nataraja@mail.eecis.udel.edu) by mail.eecis.udel.edu (Postfix) with ESMTP id B647429E6; Tue, 11 Sep 2007 19:12:10 -0400 (EDT) Message-ID: <46E720C4.5090409@cis.udel.edu> Date: Tue, 11 Sep 2007 19:12:04 -0400 From: Preethi Natarajan User-Agent: Thunderbird 1.5.0.4 (Windows/20060516) To: freebsd-net@freebsd.org X-Sanitizer: This message has been sanitized! X-Sanitizer-URL: http://mailtools.anomy.net/ X-Sanitizer-Rev: UDEL-ECECIS: Sanitizer.pm, v 1.64 2002/10/22 MIME-Version: 1.0 MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: "Paul D. Amer" Subject: TCP rcv_wnd X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 11 Sep 2007 23:41:43 -0000 Hello, I am trying to track TCP's receive window evolution in my experiments. Specifically, I want to know a connection's rwnd before processing every incoming packet. So, I put in my tracking code right after tp->rcv_wnd update in tcp_do_segment() in tcp_input.c I have packet drops in my experiment, and was hoping to see the rcv_wnd go down atleast a little bit. But rcv_wnd remains the same (net.inet.tcp.recvspace value). Was wondering if I am looking at the correct function. Any help is appreciated. Thanks -- Preethi