From owner-tcp-impl@grc.nasa.gov Mon Nov 18 08:30:42 2002 Received: from seraph2.grc.nasa.gov (seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id IAA20424 for ; Mon, 18 Nov 2002 08:30:42 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov (lombok-fi.lerc.nasa.gov [139.88.112.33]) by seraph2.grc.nasa.gov (Postfix) with ESMTP id 5757FC6937 for ; Mon, 18 Nov 2002 08:32:49 -0500 (EST) Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA GRC 8.12.3/8.12.3) id gAIDCfDU012148 for tcp-impl-outgoing; Mon, 18 Nov 2002 08:12:41 -0500 (EST) Received: from acs-viruswall.grc.nasa.gov (acs-viruswall.lerc.nasa.gov [139.88.112.21]) by lombok-fi.lerc.nasa.gov (NASA GRC 8.12.3/8.12.3) with ESMTP id gAIDCdwg012144 for ; Mon, 18 Nov 2002 08:12:40 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA GRC 8.12.3/8.12.3) with ESMTP id gAIDCcSl016479 for ; Mon, 18 Nov 2002 08:12:38 -0500 (EST) Received: from leonis.nus.edu.sg (leonis.nus.edu.sg [137.132.1.18]) by seraph3.grc.nasa.gov (Postfix) with ESMTP id BC2F9640B9 for ; Mon, 18 Nov 2002 08:12:36 -0500 (EST) Received: from pod.ddns.comp.nus.edu.sg (pod.ddns.comp.nus.edu.sg [137.132.81.90]) by leonis.nus.edu.sg (8.12.1/8.12.1) with SMTP id gAIDE0BK011856 for ; Mon, 18 Nov 2002 21:14:00 +0800 (SGT) Date: Mon, 18 Nov 2002 21:13:23 +0800 From: Gokul Poduval To: tcp-impl@grc.nasa.gov Subject: conflict between mrtt and actual rtt Message-Id: <20021118211323.0739ec68.gokulpod@comp.nus.edu.sg> Organization: National University of Singapore X-Mailer: Sylpheed version 0.8.5 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Hello, I am trying to implement some fairness policies in the 2.4 linux kernel. For this, I have two hosts between which I have fixed the RTT as about 330ms. But when I print out the mrtt in the function tcp_rtt_estimator in net/ipv4/tcp_input.c, I get mrtt as anything from 100 to 275 jiffies. converting to milliseconds, this gives me about 1000-2750 ms. Why is there a conflict here ? How do I actually measure the rtt in tcp_input.c ? Yours Sincerely, Gokul Poduval From owner-tcp-impl@grc.nasa.gov Thu Nov 28 06:19:44 2002 Received: from seraph3.grc.nasa.gov (seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id GAA25421 for ; Thu, 28 Nov 2002 06:19:44 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov (lombok-fi.lerc.nasa.gov [139.88.112.33]) by seraph3.grc.nasa.gov (Postfix) with ESMTP id 2724C6412C for ; Thu, 28 Nov 2002 06:21:54 -0500 (EST) Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA GRC 8.12.3/8.12.3) id gASB0VlC014691 for tcp-impl-outgoing; Thu, 28 Nov 2002 06:00:31 -0500 (EST) Received: from acs-viruswall.grc.nasa.gov (acs-viruswall.lerc.nasa.gov [139.88.112.21]) by lombok-fi.lerc.nasa.gov (NASA GRC 8.12.3/8.12.3) with ESMTP id gASB0Twg014687 for ; Thu, 28 Nov 2002 06:00:30 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA GRC 8.12.3/8.12.3) with ESMTP id gASB0SSl009789 for ; Thu, 28 Nov 2002 06:00:29 -0500 (EST) Received: from leonis.nus.edu.sg (leonis.nus.edu.sg [137.132.1.18]) by seraph2.grc.nasa.gov (Postfix) with ESMTP id 52BD6C693D for ; Thu, 28 Nov 2002 06:00:27 -0500 (EST) Received: from pod.ddns.comp.nus.edu.sg (pod.ddns.comp.nus.edu.sg [137.132.81.90]) by leonis.nus.edu.sg (8.12.1/8.12.1) with SMTP id gASB1p5M010240 for ; Thu, 28 Nov 2002 19:01:51 +0800 (SGT) Date: Thu, 28 Nov 2002 19:01:46 +0800 From: Gokul Poduval To: tcp-impl@grc.nasa.gov Subject: rtt in freebsd Message-Id: <20021128190146.1c6e3378.gokulpod@comp.nus.edu.sg> Organization: National University of Singapore X-Mailer: Sylpheed version 0.8.6 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Hello, In the tcpcb structure in freebsd (release 4.5), what variable maintains the instantaneous rtt ? I tried printing tp->t_rtttime in the congestion avoidance section in tcp_input.c, but it always seems to be 0. tp->t_srtt seems to reflect a more accurate value of rtt, but its value seems to be 10 times of what the actual rtt is. (if the rtt is 60ms, srtt is ~600). -- Gokul Poduval http://www.comp.nus.edu.sg/~gokulpod From owner-tcp-impl@grc.nasa.gov Thu Nov 28 23:45:20 2002 Received: from seraph3.grc.nasa.gov (seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id XAA11085 for ; Thu, 28 Nov 2002 23:45:20 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov (lombok-fi.lerc.nasa.gov [139.88.112.33]) by seraph3.grc.nasa.gov (Postfix) with ESMTP id BBDB664136 for ; Thu, 28 Nov 2002 23:47:35 -0500 (EST) Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA GRC 8.12.3/8.12.3) id gAT4Trdj016171 for tcp-impl-outgoing; Thu, 28 Nov 2002 23:29:53 -0500 (EST) Received: from acs-viruswall.grc.nasa.gov (acs-viruswall.lerc.nasa.gov [139.88.112.21]) by lombok-fi.lerc.nasa.gov (NASA GRC 8.12.3/8.12.3) with ESMTP id gAT4Tpwg016167 for ; Thu, 28 Nov 2002 23:29:51 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA GRC 8.12.3/8.12.3) with ESMTP id gAT4ToSl003705 for ; Thu, 28 Nov 2002 23:29:51 -0500 (EST) Received: from x86unx3.comp.nus.edu.sg (x86unx3.comp.nus.edu.sg [137.132.90.3]) by seraph3.grc.nasa.gov (Postfix) with ESMTP id 6B4DF640A8 for ; Thu, 28 Nov 2002 23:29:49 -0500 (EST) Received: from e500b.comp.nus.edu.sg (e500b.comp.nus.edu.sg [137.132.90.26]) by x86unx3.comp.nus.edu.sg (8.9.1/8.9.1) with SMTP id MAA09094 for ; Fri, 29 Nov 2002 12:29:47 +0800 (GMT-8) Received: from sf3.comp.nus.edu.sg(137.132.90.55) by e500b.comp.nus.edu.sg via csmap id 25176; Fri, 29 Nov 2002 12:19:10 +0800 (SGT) Received: from localhost (rahulcha@localhost) by sf3.comp.nus.edu.sg (8.8.5/8.8.5) with ESMTP id MAA24002 for ; Fri, 29 Nov 2002 12:29:47 +0800 (GMT-8) Date: Fri, 29 Nov 2002 12:29:47 +0800 (GMT-8) From: Rahul Chaudhary To: tcp-impl@grc.nasa.gov Subject: Problem in using SNOOP protocol Implementation Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi all, I am trying to use the SNOOP protocol implementation (for FreeBSD), which is given at http://nms.lcs.mit.edu/software/snoop/ The implementation provides files which are to be replaced in directories like "/usr/src/sys/netinet" , "/usr/src/sys/sys". I have replaced the original files (tcp_input.c, tcp_var.h, tcp_usrreqs.c, tcp.h, etc.> in the above mentioned directories with the new files given in this implementation. While trying to build the kernel with these new files the compilation fails. The errors which i get during compilation are : --------------------------------------------------- /usr/src/sys/netinet/in_proto.c:108: 'tcp_input' undeclared here (not in a function) /usr/src/sys/netinet/in_proto.c:108: initializer element is not constant /usr/src/sys/netinet/in_proto.c:108: (near initialization for 'inetsw[2].pr_input') /usr/src/sys/netinet/in_proto.c:108: 'tcp_ctlinput' undeclared here (not in a function) /usr/src/sys/netinet/in_proto.c:108: initializer element is not constant /usr/src/sys/netinet/in_proto.c:108: (near initialization for 'inetsw[2].pr_ctlinput') /usr/src/sys/netinet/in_proto.c:108: 'tcp_ctloutput' undeclared here (not in a function) /usr/src/sys/netinet/in_proto.c:108: initializer element is not constant /usr/src/sys/netinet/in_proto.c:108: (near initialization for 'inetsw[2].pr_ctlouotput') -------------------------------------------------------- The compilation stops after these errors. Kindly advice me on the probable reason for this problem and the solution. Thanks in Advance. Rahul Chaudhary Research Scholar Center for Internet Research School of Computing National University of Singapore Singapore-119260 email- rahulcha@comp.nus.edu.sg