From owner-freebsd-questions@FreeBSD.ORG Wed Apr 26 03:16:07 2006 Return-Path: X-Original-To: freebsd-questions@freebsd.org Delivered-To: freebsd-questions@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 1D19016A401 for ; Wed, 26 Apr 2006 03:16:07 +0000 (UTC) (envelope-from spamrefuse@yahoo.com) Received: from web33302.mail.mud.yahoo.com (web33302.mail.mud.yahoo.com [68.142.206.117]) by mx1.FreeBSD.org (Postfix) with SMTP id 9C65743D4C for ; Wed, 26 Apr 2006 03:16:06 +0000 (GMT) (envelope-from spamrefuse@yahoo.com) Received: (qmail 33138 invoked by uid 60001); 26 Apr 2006 03:16:06 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Subject:To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=AacCOKmspA4asZj1ZFKST3xr1wjesECM9anw+1VPLVYeQh0Rekh1SJ4tJxdCslzASMECJYBT5NMVaFxchrCY9ZhLzLrLkd1ikItA3NlWv8EOJ0qnR582Vref29WLIGinuoGaWKULmjVrx/0mdvH+L1vkL1W6kiSq7EAqsKFQEHM= ; Message-ID: <20060426031606.33136.qmail@web33302.mail.mud.yahoo.com> Received: from [61.72.111.233] by web33302.mail.mud.yahoo.com via HTTP; Tue, 25 Apr 2006 20:16:06 PDT Date: Tue, 25 Apr 2006 20:16:06 -0700 (PDT) From: Rob To: freebsd-questions@freebsd.org MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: 8bit Subject: How to verify speed of a 1Gb/s network? X-BeenThere: freebsd-questions@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: User questions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 26 Apr 2006 03:16:07 -0000 Hi, How can I verify that a 1Gb/s network is indeed operating at its optimal speed? I tried this: [master]$ ping -s 65507 node 65515 bytes from node: icmp_seq=0 ttl=64 time=1.97 ms 65515 bytes from node: icmp_seq=1 ttl=64 time=1.95 ms 65515 bytes from node: icmp_seq=2 ttl=64 time=1.94 ms 65515 bytes from node: icmp_seq=3 ttl=64 time=1.97 ms (I tried many times, over a long period of time to get these typical values). >From this I conclude that it takes about 1.95 ms for 65515 x 8 bits to go forth and back between master and node. Ideally, on a 1Gbit/s network, the time should be: 65515 x 8 x 2 / (10243) = 0.98 ms (x 2 for the roundtrip signal forth and back and 10243 is the 1G of the network) May I now conclude that the real-time is about two times the ideal-time? I wonder if this indicates a problem of the network? And is this a proper test of this Gbit/s network? Thanks, Rob. PS: I verified my calculation method for two computers here on a 100Mbit/s network, from which I get: time with ping: 12.4 ms ideal calculated time: 10 ms which is an acceptable difference. __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com