From owner-freebsd-net@FreeBSD.ORG Thu Nov 22 23:07:14 2012 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 19B4B76D for ; Thu, 22 Nov 2012 23:07:14 +0000 (UTC) (envelope-from if@xip.at) Received: from chile.gbit.at (ns1.xip.at [193.239.188.99]) by mx1.freebsd.org (Postfix) with ESMTP id 58BEC8FC08 for ; Thu, 22 Nov 2012 23:07:12 +0000 (UTC) Received: (qmail 25672 invoked from network); 23 Nov 2012 00:07:10 +0100 Received: from fw.xip.at (HELO ?127.0.0.1?) (89.207.145.147) by chile.gbit.at with SMTP; 23 Nov 2012 00:07:10 +0100 Message-ID: <50AEB022.6050608@xip.at> Date: Fri, 23 Nov 2012 00:07:14 +0100 From: Ingo Flaschberger User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:17.0) Gecko/17.0 Thunderbird/17.0 MIME-Version: 1.0 To: freebsd-net@freebsd.org Subject: Re: Low Bandwidth on intercontinental connections References: <50ACF62C.8000408@mpeters.org> <50ad087d.1892cc0a.2cce.3bf2@mx.google.com> <50AD1012.7020209@mpeters.org> <50AD14F8.8050001@xip.at> <50ADE5E4.9090708@mpeters.org> <50AE0B12.8000309@xip.at> <50AE1CCC.7080706@mpeters.org> <50AE2686.8070007@xip.at> <50AE47D4.7080608@mpeters.org> In-Reply-To: <50AE47D4.7080608@mpeters.org> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 22 Nov 2012 23:07:14 -0000 > nearly every packet is fragmented, if i read th [TCP segment of a > reassembled PDU] correct. Those have a length of 1364. Thera are also > lots of [TCP Window Update] (every two to three acks from the receiving > host, where the tcpdump took place). After some time, there were lots of > [TCP Dup ACK] from the receiving host and the throughput went to a crawl > and had lots of retransmissions. After 30 sec. everything went back to > "normal" as of transmitting pakets without dubs and retransmissions. how you can detect fragmented packets: tcpdump at sender and at receiver site. If you send 1500 byte packets but receive 2 differnt sized packets (a bigger and a smaller one) at the other site - than there is fragmentation. 1364 packet length seems strage, as your max icmp packet is 1322 byte + 20byte IP header + 8byte icmp = mtu 1350? > The same tcpdump collect on the Linux hosts, the packets had a length of > 1514 and no dubs or retransmissions. 1514? max mtu on ethernet is 1500 can you send me (directly) a send and receive site tcpdump from linux and freebsd for a whole data-transfer? Kind regards, Ingo Flaschberger