From owner-freebsd-net@FreeBSD.ORG Fri Dec 26 05:12:19 2003 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 2FE4F16A4CE for ; Fri, 26 Dec 2003 05:12:19 -0800 (PST) Received: from moutng.kundenserver.de (moutng.kundenserver.de [212.227.126.187]) by mx1.FreeBSD.org (Postfix) with ESMTP id C7A5E43D39 for ; Fri, 26 Dec 2003 05:12:15 -0800 (PST) (envelope-from max@love2party.net) Received: from [212.227.126.162] (helo=mrelayng.kundenserver.de) by moutng.kundenserver.de with esmtp (Exim 3.35 #1) id 1AZrlH-00048O-00 for freebsd-net@freebsd.org; Fri, 26 Dec 2003 14:12:15 +0100 Received: from [217.83.3.47] (helo=vampire.homelinux.org) by mrelayng.kundenserver.de with asmtp (Exim 3.35 #1) id 1AZrlG-0006p7-00 for freebsd-net@freebsd.org; Fri, 26 Dec 2003 14:12:14 +0100 Received: (qmail 53980 invoked from network); 26 Dec 2003 13:16:35 -0000 Received: from unknown (HELO fbsd52.laiers.local) (192.168.4.88) by 192.168.4.1 with SMTP; 26 Dec 2003 13:16:35 -0000 From: Max Laier To: "Tanmay Ganacharya" Date: Fri, 26 Dec 2003 14:12:10 +0100 User-Agent: KMail/1.5.4 References: In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200312261412.10182.max@love2party.net> X-Provags-ID: kundenserver.de abuse@kundenserver.de auth:e28873fbe4dbe612ce62ab869898ff08 cc: freebsd-net@freebsd.org cc: freebsd-current@freebsd.org Subject: Re: Recording RTT and RTO values X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 26 Dec 2003 13:12:19 -0000 On Friday 26 December 2003 11:49, Tanmay Ganacharya wrote: > Hello, > > I am a student from the University of Southern California. I am currently > pursuing my master. > I am working on a project in which I need to record the RTT and RTO values > of a TCP connection. > To achieve the same I first re-compiled my kernel to support debug mode. > I then used a simple client server socket program to transfer a file. The > sockets had the debug option set. > Thus the kernel logs were then collected using the trpt command. > But the problem is I am not able to figure out the required RTT and RTO > values from the log. > > The log looks somewhat like the following > 762 ESTABLISHED:input (src=128.8.126.6,32858, > dst=204.57.0.2,1666)f5ac168b@5269bce1(win=f8e0) -> ESTABLISHED > rcv_nxt f5ac168b rcv_wnd e240 snd_una 5269bce1 snd_nxt 5269d381 snd_max > 5269d381 > snd_wl1 f5ac168b snd_wl2 5269bce1 snd_wnd f8e0 > > 762 ESTABLISHED:output (src=204.57.0.2,1666, > dst=128.8.126.6,32858)[5269d381..5269d36d)@f5ac168b(win=e240) -> > ESTABLISHED > rcv_nxt f5ac168b rcv_wnd e240 snd_una 5269bce1 snd_nxt 5269d929 snd_max > 5269d929 > snd_wl1 f5ac168b snd_wl2 5269bce1 snd_wnd f8e0 > > I am really not able to understand which are the RTT and RTO values in > these. > Please if anyone knows do let me know. It would really be useful. > Also if anyone knows any other methods of recording the RTT and RTO values > of a connection > please do let me know abt it. > I would really be grateful. CC: net@ (current@ isn't exactly the list for this). None of these values are the RTT or RTO values of the connection as the debug is rather sequence number centric. Take a look at "src/sys/netinet/tcp_var.h: struct tcpcb", where you will find short explainations for each field. The value you might be looking for is "int t_rtttime". Modify the printf's in tcp_debug.c to give you the values you need and recompile your kernel. Hope this helps. -- Best regards, | max@love2party.net Max Laier | ICQ #67774661 http://pf4freebsd.love2party.net/ | mlaier@EFnet #DragonFlyBSD