From owner-freebsd-net Tue Oct 12 7:35: 6 1999 Delivered-To: freebsd-net@freebsd.org Received: from etek.chalmers.se (quarl0.etek.chalmers.se [129.16.32.20]) by hub.freebsd.org (Postfix) with ESMTP id 27C1C15752 for ; Tue, 12 Oct 1999 07:34:52 -0700 (PDT) (envelope-from em8jaci@etek.chalmers.se) Received: from jaci.rotary.studenthem.gu.se (nat.studenthem.gu.se [193.10.163.20]) by etek.chalmers.se (8.8.8/8.8.8) with ESMTP id QAA13694 for ; Tue, 12 Oct 1999 16:34:11 +0200 (MET DST) X-Authentication-Warning: quarl0.etek.chalmers.se: Host nat.studenthem.gu.se [193.10.163.20] claimed to be jaci.rotary.studenthem.gu.se Date: Tue, 12 Oct 1999 16:28:45 +0200 From: Jacopo Pecci X-Mailer: The Bat! (v1.36) S/N 6B091D52 / Educational Reply-To: Jacopo Pecci X-Priority: 3 (Normal) Message-ID: <8686.991012@etek.chalmers.se> To: net@freebsd.org Subject: delayed ACKs Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.org According to what I have studied, delayed ACKs can be sent: (1)every 200 ms (2)when I have data to send (piggyback packet) (3)every second packet so I don't understand why in the example below, there are ACKs that acknowledge up to 7 segments. (in the example I have just sent 50 segments of 1460 bytes from the client to the server) 15:58:26.565899 172.20.1.15.1034 > 172.20.2.15.1111: S 1085244744:1085244744(0) win 16384 (DF) 15:58:26.566236 172.20.2.15.1111 > 172.20.1.15.1034: S 242000411:242000411(0) ack 1085244745 win 17520 (DF) 15:58:26.566438 172.20.1.15.1034 > 172.20.2.15.1111: . ack 1 win 17520 (DF) 15:58:26.662625 172.20.1.15.1034 > 172.20.2.15.1111: . 1:1461(1460) ack 1 win 17520 (DF) 15:58:26.781386 172.20.2.15.1111 > 172.20.1.15.1034: . ack 1461 win 17520 (DF) ^^^^^^^ 15:58:26.782287 172.20.1.15.1034 > 172.20.2.15.1111: . 1461:2921(1460) ack 1 win 17520 (DF) 15:58:26.783086 172.20.1.15.1034 > 172.20.2.15.1111: . 2921:4381(1460) ack 1 win 17520 (DF) 15:58:26.784675 172.20.2.15.1111 > 172.20.1.15.1034: . ack 4381 win 17520 (DF) ^^^^^^^^^ 15:58:26.785521 172.20.1.15.1034 > 172.20.2.15.1111: . 4381:5841(1460) ack 1 win 17520 (DF) 15:58:26.786299 172.20.1.15.1034 > 172.20.2.15.1111: . 5841:7301(1460) ack 1 win 17520 (DF) 15:58:26.787074 172.20.1.15.1034 > 172.20.2.15.1111: . 7301:8761(1460) ack 1 win 17520 (DF) 15:58:26.788639 172.20.2.15.1111 > 172.20.1.15.1034: . ack 7301 win 17520 (DF) ^^^^^^^^^^^ 15:58:26.789477 172.20.1.15.1034 > 172.20.2.15.1111: . 8761:10221(1460) ack 1 win 17520 (DF) 15:58:26.790255 172.20.1.15.1034 > 172.20.2.15.1111: . 10221:11681(1460) ack 1 win 17520 (DF) 15:58:26.791029 172.20.1.15.1034 > 172.20.2.15.1111: . 11681:13141(1460) ack 1 win 17520 (DF) 15:58:26.792614 172.20.2.15.1111 > 172.20.1.15.1034: . ack 10221 win 17520 (DF) ....... ^^^^^^^^^^^ according with point (3) each ACK acknowledges 2 packets but later.... 15:58:26.793455 172.20.1.15.1034 > 172.20.2.15.1111: . 13141:14601(1460) ack 1 win 17520 (DF) 15:58:26.794232 172.20.1.15.1034 > 172.20.2.15.1111: . 14601:16061(1460) ack 1 win 17520 (DF) 15:58:26.795007 172.20.1.15.1034 > 172.20.2.15.1111: . 16061:17521(1460) ack 1 win 17520 (DF) 15:58:26.796695 172.20.2.15.1111 > 172.20.1.15.1034: . ack 13141 win 17520 (DF) 15:58:26.796750 172.20.2.15.1111 > 172.20.1.15.1034: . ack 16061 win 17520 (DF) ^^^^^^^^^^^ 15:58:26.797580 172.20.1.15.1034 > 172.20.2.15.1111: . 17521:18981(1460) ack 1 win 17520 (DF) 15:58:26.798349 172.20.1.15.1034 > 172.20.2.15.1111: . 18981:20441(1460) ack 1 win 17520 (DF) 15:58:26.799119 172.20.1.15.1034 > 172.20.2.15.1111: . 20441:21901(1460) ack 1 win 17520 (DF) 15:58:26.800083 172.20.1.15.1034 > 172.20.2.15.1111: . 21901:23361(1460) ack 1 win 17520 (DF) 15:58:26.801295 172.20.1.15.1034 > 172.20.2.15.1111: . 23361:24821(1460) ack 1 win 17520 (DF) 15:58:26.802540 172.20.1.15.1034 > 172.20.2.15.1111: . 24821:26281(1460) ack 1 win 17520 (DF) 15:58:26.865477 172.20.2.15.1111 > 172.20.1.15.1034: . ack 26281 win 10372 (DF) ^^^^^^^^^^ 15:58:26.866343 172.20.1.15.1034 > 172.20.2.15.1111: . 26281:27741(1460) ack 1 win 17520 (DF) 15:58:26.867117 172.20.1.15.1034 > 172.20.2.15.1111: . 27741:29201(1460) ack 1 win 17520 (DF) 15:58:26.867886 172.20.1.15.1034 > 172.20.2.15.1111: . 29201:30661(1460) ack 1 win 17520 (DF) 15:58:26.868837 172.20.1.15.1034 > 172.20.2.15.1111: . 30661:32121(1460) ack 1 win 17520 (DF) 15:58:26.870080 172.20.1.15.1034 > 172.20.2.15.1111: P 32121:33581(1460) ack 1 win 17520 (DF) 15:58:26.871290 172.20.1.15.1034 > 172.20.2.15.1111: . 33581:35041(1460) ack 1 win 17520 (DF) 15:58:26.872534 172.20.1.15.1034 > 172.20.2.15.1111: . 35041:36501(1460) ack 1 win 17520 (DF) 15:58:26.928674 172.20.2.15.1111 > 172.20.1.15.1034: . ack 36501 win 3224 (DF) ^^^^^^^^^^^^ 15:58:26.928732 172.20.2.15.1111 > 172.20.1.15.1034: . ack 36501 win 6296 (DF) ... it acknowledges first 16061 and then 26281 (7 segments) thanks /jaci To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message