From owner-tcp-impl@grc.nasa.gov Thu Nov 1 02:13:19 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id CAA25761 for ; Thu, 1 Nov 2001 02:13:19 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 71B03C69E6; Thu, 1 Nov 2001 02:12:10 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA64aiY4; Thu, 1 Nov 01 02:12:10 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id BAA21714 for tcp-impl-outgoing; Thu, 1 Nov 2001 01:58:08 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id BAA21700 for ; Thu, 1 Nov 2001 01:58:07 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id BAA01146 for ; Thu, 1 Nov 2001 01:58:03 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 6A76FC6959; Thu, 1 Nov 2001 01:55:51 -0500 (EST) Received: from unknown(202.125.87.14) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAASDaih2; Thu, 1 Nov 01 01:55:49 -0500 Received: from sarayu.qpackets.com (machine248 [172.16.1.248]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id MAA15046; Thu, 1 Nov 2001 12:29:41 +0530 Message-Id: <5.1.0.14.0.20011101121740.00a7e020@64.170.220.2> X-Sender: srinia@64.170.220.4 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 01 Nov 2001 12:26:37 +0530 To: tcp-impl@grc.nasa.gov From: Srinivas Subject: Req: Doubt regarding the USER call (send call) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi, This is srinivas from INDIA. Here my doubt follows. Doubt regarding the user calls (send call without urgent data and next send call with urgent data). Take a case that TCP "A" and TCP "B" both are in established state. Application sitting over "A" has given send call (without urgent bit) of 16k bytes. But the tcp stack of "A" is sending data to "B" of 536 bytes due to MTU of the path. (that is the MTU between "A" and "B" is 536).So TCP "A" takes some time to send all the 16k bytes to the distant end. take a instant, that TCP "A" has sent 5k bytes and ready to send the next 536 bytes segment. At this instant Application sitting over the TCP"A" has given send call with urgent data of 10 bytes. So Here comes my doubt. Should TCP"A" has to send this data at this instant or It should queue this data and sent after the remaining 11k bytes of data??? I think my question is clear. Thanks and regards Srinivas From owner-tcp-impl@grc.nasa.gov Thu Nov 1 02:38:35 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id CAA28695 for ; Thu, 1 Nov 2001 02:38:34 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id B3746C695D; Thu, 1 Nov 2001 02:38:36 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAykaiEc; Thu, 1 Nov 01 02:38:36 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id CAA24982 for tcp-impl-outgoing; Thu, 1 Nov 2001 02:29:43 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id CAA24968 for ; Thu, 1 Nov 2001 02:29:42 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id CAA02799 for ; Thu, 1 Nov 2001 02:29:39 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 598AA6414B; Thu, 1 Nov 2001 02:28:57 -0500 (EST) Received: from unknown(202.125.87.14) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAARraO5H; Thu, 1 Nov 01 02:28:55 -0500 Received: from sarayu.trinc.com (machine248 [172.16.1.248]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id NAA15377 for ; Thu, 1 Nov 2001 13:03:02 +0530 Message-Id: <5.1.0.14.0.20011101123256.00a78440@64.170.220.2> X-Sender: srinia@64.170.220.2 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 01 Nov 2001 12:59:57 +0530 To: tcp-impl@grc.nasa.gov From: Srinivas Amaravadi Subject: Req: Any books or sites for USER calls. Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi, Any books for user calls (section 3.9 of RFC 793. Event processing, Page 52) which will give a little bit of explanation. Thanks. Regards, Srinivas . From owner-tcp-impl@grc.nasa.gov Fri Nov 2 10:54:02 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id KAA08540 for ; Fri, 2 Nov 2001 10:54:02 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id DC116C6AFF; Fri, 2 Nov 2001 10:53:41 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAANiaqVw; Fri, 2 Nov 01 10:53:41 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id KAA28958 for tcp-impl-outgoing; Fri, 2 Nov 2001 10:30:52 -0500 (EST) Received: from seraph3.grc.nasa.gov (firewall-user@guardian03.lerc.nasa.gov [139.88.146.12]) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) with ESMTP id KAA28929 for ; Fri, 2 Nov 2001 10:30:50 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id C7891649FE; Fri, 2 Nov 2001 03:53:41 -0500 (EST) Received: from unknown(202.125.87.14) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAA5xa4FH; Fri, 2 Nov 01 03:53:39 -0500 Received: from sarayu.trinc.com (machine248 [172.16.1.248]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id OAA24605 for ; Fri, 2 Nov 2001 14:27:48 +0530 Message-Id: <5.1.0.14.0.20011102142209.00a8bec0@64.170.220.2> X-Sender: srinia@64.170.220.2 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Fri, 02 Nov 2001 14:24:29 +0530 To: tcp-impl@grc.nasa.gov From: Srinivas Amaravadi Subject: Req: How to join this group !!! Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi, This is A.Srinivas from INIDA. I want to join this group, that is how can i get the questions and answers posted to this group. Thanks Regards, Srinivas From owner-tcp-impl@grc.nasa.gov Tue Nov 6 03:02:47 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id DAA03889 for ; Tue, 6 Nov 2001 03:02:46 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 0250B640C1; Tue, 6 Nov 2001 03:02:48 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAcEai_x; Tue, 6 Nov 01 03:02:48 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id CAA01031 for tcp-impl-outgoing; Tue, 6 Nov 2001 02:46:30 -0500 (EST) Received: from seraph2.grc.nasa.gov (firewall-user@guardian02.lerc.nasa.gov [139.88.146.11]) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) with ESMTP id CAA01027 for ; Tue, 6 Nov 2001 02:46:28 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 2DA9EC68F6; Tue, 6 Nov 2001 02:46:26 -0500 (EST) Received: from unknown(202.125.87.14) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA6gaiTK; Tue, 6 Nov 01 02:46:24 -0500 Received: from sarayu.qpackets.com (machine248 [172.16.1.248]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id NAA14088 for ; Tue, 6 Nov 2001 13:20:39 +0530 Message-Id: <5.1.0.14.0.20011106131617.00a4eac0@64.170.220.2> X-Sender: srinia@64.170.220.4 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Tue, 06 Nov 2001 13:17:35 +0530 To: tcp-impl@grc.nasa.gov From: Srinivas Subject: Re: Req: How to join this group !!! Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hello Sir, Thanks for ur reply. Sorry to disturb you, i am unable to find out the way from RFC 2142.Please help me in joining this group. Thanks regards, Srinivas At 12:47 PM 11/2/01 -0500, you wrote: > To: tcp-impl@grc.nasa.gov > I want to join this group, that is how can i get the questions and > answers posted to this group. See RFC2142 section 6. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse@rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B From owner-tcp-impl@grc.nasa.gov Tue Nov 6 15:01:22 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id PAA00930 for ; Tue, 6 Nov 2001 15:01:21 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 62D27640F5; Tue, 6 Nov 2001 14:58:53 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAx0aWrQ; Tue, 6 Nov 01 14:58:53 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id OAA20993 for tcp-impl-outgoing; Tue, 6 Nov 2001 14:45:08 -0500 (EST) Received: from seraph3.grc.nasa.gov (firewall-user@guardian03.lerc.nasa.gov [139.88.146.12]) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) with ESMTP id OAA20989 for ; Tue, 6 Nov 2001 14:45:07 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 4E3E9640C4; Tue, 6 Nov 2001 14:45:07 -0500 (EST) Received: from mail2.mangoosta.net(217.11.161.6) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAATga4VM; Tue, 6 Nov 01 14:45:06 -0500 Received: from [217.11.167.88] (helo=Philippr.mangoosta.fr) by mail.mangoosta.net id 161Jel-0001WJ-00 for tcp-impl@grc.nasa.gov; Tue, 06 Nov 2001 21:45:39 -0600 Message-Id: <4.3.2.7.2.20011106202621.00ac83a0@mail.mangoosta.net> X-Sender: pragon@mail.mangoosta.net X-Mailer: QUALCOMM Windows Eudora Version 4.3.2 Date: Tue, 06 Nov 2001 20:46:29 +0100 To: tcp-impl@grc.nasa.gov From: Ragon Philippe Subject: Question about Solaris' way to compute RTO Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk I am involved into TCP applications testing over a wireless network. I am stumbling over a 'systematic' problem related to Solaris 2.6 when it is used as a server : I am regurlarly getting spurrious retransmissions (Ack arriving a few tens of ms after the server has decided to retransmit) with a huge performance loss as a consequence. This problem does not occur with Solaris 8, Linux or Windows NT 4 servers. I have checked with traces and the use of Solaris' command 'ndd /dev/tcp tcp_status' that : - Solaris 2.6 is taking one RTT sample per packet - Solaris 2.6 seems to be RFC 2988 compliant in its computation of RTO from its RTT measurements (alpha =1/8, beta = 1/4, K= 4 and clock granularity is100 ms) I am eager to get any information on how : - Solaris 2.6 is actually computing RTO and whether there are some parameters to tune this computation. - how Solaris 8 is different from Solaris 2.6 from this point of view Any help will be appreciated. --------------------------------------------------------------------- Philippe Ragon / Tour Atlas / 10, villa d'Este/ 75013 Paris/ FRANCE Telephone & Fax : (33) 01 45 70 79 53 E-mail : pragon@mangoosta.fr --------------------------------------------------------------------- From owner-tcp-impl@grc.nasa.gov Wed Nov 7 04:20:34 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id EAA29765 for ; Wed, 7 Nov 2001 04:20:33 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id F1963C6942; Wed, 7 Nov 2001 04:19:01 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAnRailQ; Wed, 7 Nov 01 04:19:01 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id EAA06398 for tcp-impl-outgoing; Wed, 7 Nov 2001 04:06:02 -0500 (EST) Received: from seraph3.grc.nasa.gov (firewall-user@guardian03.lerc.nasa.gov [139.88.146.12]) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) with ESMTP id EAA06394 for ; Wed, 7 Nov 2001 04:06:01 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 6EFBD640D2; Wed, 7 Nov 2001 04:06:01 -0500 (EST) Received: from unknown(202.125.87.14) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAADOaqUG; Wed, 7 Nov 01 04:05:59 -0500 Received: from sarayu.qpackets.com (machine248 [172.16.1.248]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id OAA25918 for ; Wed, 7 Nov 2001 14:39:04 +0530 Message-Id: <5.1.0.14.0.20011107143546.00a83140@64.170.220.4> X-Sender: srinia@64.170.220.4 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Wed, 07 Nov 2001 14:36:03 +0530 To: tcp-impl@grc.nasa.gov From: Srinivas Subject: Doubt regarding the time out option in OPEN call (user call) Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk > >Hi, > >This is regarding the OPEN call (user call). In open call there is a >timeout option. > >in RFC 793 it is stated that (page 45, open) :- > > The timeout, if present, permits the caller to set up a timeout > for all data submitted to TCP. If data is not successfully > delivered to the destination within the timeout period, the TCP > will abort the connection. The present global default is five > minutes. > >here comes my doubt: is it the timeout for the entire connection ( that >is with in that timeout whole data of that particular connection has to >send to remote tcp )?? or within in the time out SYN segment should be >sent to the destination??? > >i think i am clear. > >Thanks > >regards, >Srinivas From owner-tcp-impl@grc.nasa.gov Wed Nov 7 11:40:48 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id LAA15353 for ; Wed, 7 Nov 2001 11:40:47 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 4EF97C69E4; Wed, 7 Nov 2001 11:38:55 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAOwaGZ4; Wed, 7 Nov 01 11:38:55 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id LAA13328 for tcp-impl-outgoing; Wed, 7 Nov 2001 11:27:00 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id LAA13300 for ; Wed, 7 Nov 2001 11:26:58 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id LAA23594 for ; Wed, 7 Nov 2001 11:26:52 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 396CDC6918; Wed, 7 Nov 2001 11:26:48 -0500 (EST) Received: from louie.udel.edu(128.4.40.12) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAYYaav1; Wed, 7 Nov 01 11:26:47 -0500 Received: from louie.udel.edu by mail.eecis.udel.edu id aa17867; 7 Nov 2001 11:17 EST Date: Wed, 7 Nov 2001 11:17:58 -0500 (EST) From: Constantinos Dovrolis To: tcp-impl@grc.nasa.gov MMDF-Warning: Parse error in original version of preceding line at mail.eecis.udel.edu Cc: Hao Jiang Subject: 3-way handshake delays Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi all, we have a question about the generation of the SYN-ACK packet at the callee. Is it always true that the callee sends the SYN-ACK packet immediately after receiving the SYN packet? I am not referring to delays that can be caused by other higher-priority activity at the kernel, but about delays that would be caused by the code that processes the SYN packet and sends the SYN-ACK packet. Similarly, is it always true that the caller sends the first ACK packet immediately after receicing the SYN-ACK packet? Thanks much, Constantinos Computer and Information Sciences - University of Delaware http://www.cis.udel.edu/~dovrolis/ From owner-tcp-impl@grc.nasa.gov Wed Nov 7 12:02:45 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id MAA16283 for ; Wed, 7 Nov 2001 12:02:44 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id F0D766410D; Wed, 7 Nov 2001 11:59:11 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAVya4l1; Wed, 7 Nov 01 11:59:11 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id LAA20508 for tcp-impl-outgoing; Wed, 7 Nov 2001 11:51:24 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id LAA20488 for ; Wed, 7 Nov 2001 11:51:18 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id LAA26579 for ; Wed, 7 Nov 2001 11:51:02 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id C2DCEC6919; Wed, 7 Nov 2001 11:51:01 -0500 (EST) Received: from boreas.isi.edu(128.9.160.161) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA0RaaNb; Wed, 7 Nov 01 11:51:01 -0500 Received: from isi.edu (c1-vpn1.isi.edu [128.9.176.27]) by boreas.isi.edu (8.11.6/8.11.2) with ESMTP id fA7GotO19736; Wed, 7 Nov 2001 08:50:56 -0800 (PST) Message-ID: <3BE96664.4030508@isi.edu> Date: Wed, 07 Nov 2001 08:50:44 -0800 From: Joe Touch User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.2) Gecko/20010726 Netscape6/6.1 X-Accept-Language: en-us MIME-Version: 1.0 To: Constantinos Dovrolis Cc: tcp-impl@grc.nasa.gov, Hao Jiang Subject: Re: 3-way handshake delays References: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Constantinos Dovrolis wrote: > Hi all, > > we have a question about the generation of the SYN-ACK > packet at the callee. > > Is it always true that the callee sends the SYN-ACK packet > immediately after receiving the SYN packet? I am not > referring to delays that can be caused by other > higher-priority activity at the kernel, but about delays > that would be caused by the code that processes the > SYN packet and sends the SYN-ACK packet. > > Similarly, is it always true that the caller sends the > first ACK packet immediately after receicing the SYN-ACK > packet? Are you asking about a timeliness requirement, or about typical implementations? Once the packet is being processed by TCP, the process-send exchange is typically immediate. The process/update state/emit packet exchange is considered atomic in RFC793, although there could be intermediate internal states, they don't serve much use given the input and output IP queues. However there can be delays in those IP queues. If there is a noticible delay, these might be the place to check first. Joe From owner-tcp-impl@grc.nasa.gov Wed Nov 7 14:02:08 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id OAA20564 for ; Wed, 7 Nov 2001 14:02:08 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 3B333C68F1; Wed, 7 Nov 2001 14:01:47 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAXgaaVU; Wed, 7 Nov 01 14:01:47 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id NAA16664 for tcp-impl-outgoing; Wed, 7 Nov 2001 13:51:53 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id NAA16652 for ; Wed, 7 Nov 2001 13:51:52 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id NAA06967 for ; Wed, 7 Nov 2001 13:51:50 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 3FB616410C; Wed, 7 Nov 2001 13:50:26 -0500 (EST) Received: from aland.bbn.com(204.162.9.10) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAtSai3o; Wed, 7 Nov 01 13:50:25 -0500 Received: from aland.bbn.com (localhost [127.0.0.1]) by aland.bbn.com (8.11.3/8.11.3) with ESMTP id fA7IoJq74826; Wed, 7 Nov 2001 13:50:19 -0500 (EST) Message-Id: <200111071850.fA7IoJq74826@aland.bbn.com> To: Constantinos Dovrolis Cc: tcp-impl@grc.nasa.gov, Hao Jiang Subject: Re: 3-way handshake delays In-Reply-To: Your message of "Wed, 07 Nov 2001 11:17:58 EST." Date: Wed, 07 Nov 2001 13:50:19 -0500 From: Craig Partridge Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk In message , Constantin os Dovrolis writes: >Similarly, is it always true that the caller sends the >first ACK packet immediately after receicing the SYN-ACK >packet? It is a long time since I've looked at this issue, but I believe it is perfectly acceptable to pause very briefly before sending back the ACK to piggy-back data with the ACK. I don't know of any implementation that does so, however. Craig From owner-tcp-impl@grc.nasa.gov Wed Nov 7 14:18:36 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id OAA21026 for ; Wed, 7 Nov 2001 14:18:35 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 36A6A641B5; Wed, 7 Nov 2001 14:18:15 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAATsaORw; Wed, 7 Nov 01 14:18:14 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id OAA21646 for tcp-impl-outgoing; Wed, 7 Nov 2001 14:11:09 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id OAA21630 for ; Wed, 7 Nov 2001 14:11:08 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id OAA08809 for ; Wed, 7 Nov 2001 14:11:02 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id B94A2C6955; Wed, 7 Nov 2001 14:10:34 -0500 (EST) Received: from igw3.watson.ibm.com(198.81.209.18) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAK2aiAX; Wed, 7 Nov 01 14:10:34 -0500 Received: from sp1n189at0.watson.ibm.com (sp1n189at0.watson.ibm.com [9.2.104.62]) by igw3.watson.ibm.com (8.11.4/8.11.4) with ESMTP id fA7JA3R13674; Wed, 7 Nov 2001 14:10:03 -0500 Received: from orinoco.watson.ibm.com (orinoco.watson.ibm.com [9.2.16.142]) by sp1n189at0.watson.ibm.com (8.11.4/8.11.4) with ESMTP id fA7JA3f94932; Wed, 7 Nov 2001 14:10:03 -0500 Received: (from nahum@localhost) by orinoco.watson.ibm.com (AIX4.3/8.9.3/8.9.3/01-10-2000) id OAA30594; Wed, 7 Nov 2001 14:10:03 -0500 From: Erich Nahum Message-Id: <200111071910.OAA30594@orinoco.watson.ibm.com> Subject: Re: 3-way handshake delays To: craig@aland.bbn.com (Craig Partridge) Date: Wed, 7 Nov 2001 14:10:03 -0500 (EST) Cc: dovrolis@mail.eecis.udel.edu (Constantinos Dovrolis), tcp-impl@grc.nasa.gov, hjiang@mail.eecis.udel.edu (Hao Jiang) In-Reply-To: <200111071850.fA7IoJq74826@aland.bbn.com> from "Craig Partridge" at Nov 07, 2001 01:50:19 PM Reply-To: nahum@watson.ibm.com (Erich M. Nahum) X-Url: http://www.research.ibm.com/people/n/nahum/ X-Mailer: ELM [version 2.5 PL2] 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 Craig Partridge writes: > > >Similarly, is it always true that the caller sends the > >first ACK packet immediately after receicing the SYN-ACK > >packet? > > It is a long time since I've looked at this issue, but I believe it is > perfectly acceptable to pause very briefly before sending back the ACK to > piggy-back data with the ACK. I don't know of any implementation that > does so, however. There's at least one that does so: AIX. It's run-time configurable. I have a paper that includes this very topic that will appear in ToN soon. FreeBSD may have something similar as well. More broadly, the SYN-ACK may be delayed an arbitrary amount of time depending on the implementation. For example, some implementations run their networking code off the interrupt stack, which provides a very quick response, while others may use a kernel thread of some kind (e.g. BSD soft interrupts or linux bottom-half handlers). If you do the latter and you're hit with a lot of hardware interrupts, it may take some time to respond to the SYN. -Erich -- Erich M. Nahum IBM T.J. Watson Research Center Networking Research P.O. Box 704 nahum@watson.ibm.com Yorktown Heights NY 10598 From owner-tcp-impl@grc.nasa.gov Wed Nov 7 14:21:41 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id OAA21092 for ; Wed, 7 Nov 2001 14:21:41 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id D5846C6A2B; Wed, 7 Nov 2001 14:18:12 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAkVaqCa; Wed, 7 Nov 01 14:18:12 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id OAA22149 for tcp-impl-outgoing; Wed, 7 Nov 2001 14:11:55 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id OAA22135 for ; Wed, 7 Nov 2001 14:11:54 -0500 (EST) From: kuznet@ms2.inr.ac.ru Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id OAA09115 for ; Wed, 7 Nov 2001 14:11:50 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 86BA06414A; Wed, 7 Nov 2001 14:06:49 -0500 (EST) Received: from minus.inr.ac.ru(193.233.7.97) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAApRayMt; Wed, 7 Nov 01 14:06:48 -0500 Received: (from kuznet@localhost) by ms2.inr.ac.ru (8.6.13/ANK) id WAA07871; Wed, 7 Nov 2001 22:06:23 +0300 Message-Id: <200111071906.WAA07871@ms2.inr.ac.ru> Subject: Re: 3-way handshake delays To: craig@aland.bbn.com (Craig Partridge) Date: Wed, 7 Nov 2001 22:06:23 +0300 (MSK) Cc: dovrolis@mail.eecis.udel.edu, tcp-impl@grc.nasa.gov, hjiang@mail.eecis.udel.edu In-Reply-To: <200111071850.fA7IoJq74826@aland.bbn.com> from "Craig Partridge" at Nov 7, 1 01:50:19 pm X-Mailer: ELM [version 2.4 PL24] MIME-Version: 1.0 Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hello! > piggy-back data with the ACK. I don't know of any implementation that > does so, however. Linux does this, but only if application set a special option on socket telling that active connector is going to send data first. Alexey From owner-tcp-impl@grc.nasa.gov Wed Nov 7 16:31:31 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id QAA24266 for ; Wed, 7 Nov 2001 16:31:31 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id E43BEC692C; Wed, 7 Nov 2001 16:31:33 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAkhaG_U; Wed, 7 Nov 01 16:31:33 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id QAA25910 for tcp-impl-outgoing; Wed, 7 Nov 2001 16:19:49 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id QAA25881 for ; Wed, 7 Nov 2001 16:19:47 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id QAA22075 for ; Wed, 7 Nov 2001 16:19:44 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 02345C6941; Wed, 7 Nov 2001 16:18:25 -0500 (EST) Received: from h-135-207-30-103.research.att.com(135.207.30.103) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA9UaqXR; Wed, 7 Nov 01 16:18:25 -0500 Received: from alliance.research.att.com (alliance.research.att.com [135.207.26.26]) by mail-green.research.att.com (Postfix) with ESMTP id 513D21E06D; Wed, 7 Nov 2001 16:18:19 -0500 (EST) Received: from windsor.research.att.com (windsor.research.att.com [135.207.26.46]) by alliance.research.att.com (8.8.7/8.8.7) with ESMTP id QAA02192; Wed, 7 Nov 2001 16:18:18 -0500 (EST) From: Bill Fenner Received: (from fenner@localhost) by windsor.research.att.com (8.8.8+Sun/8.8.5) id NAA19703; Wed, 7 Nov 2001 13:18:18 -0800 (PST) Message-Id: <200111072118.NAA19703@windsor.research.att.com> MIME-Version: 1.0 Content-Type: text/plain; charset=US-ASCII To: dovrolis@mail.eecis.udel.edu Subject: Re: 3-way handshake delays Cc: tcp-impl@grc.nasa.gov, hjiang@mail.eecis.udel.edu Date: Wed, 7 Nov 2001 13:18:17 -0800 Versions: dmail (solaris) 2.2j/makemail 2.9b Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Some time ago, I remember seeing an idea which would cause this kind of 3-way handshake delays. I don't remember who suggested it or where. Basically, the idea is to only send the SYN/ACK after the first I/O is posted to the socket (read, write, probably select). It "should" be backwards-compatible, since programs usually do an I/O immediately after accept(), but programs aware of the different API could, e.g., close the connection (causing a RST, perhaps) based on IP address access control (or some such), causing an attacker to think that the port is closed. I never heard of an implementation of this, but I've always thought it was a potentially neat idea. Bill From owner-tcp-impl@grc.nasa.gov Wed Nov 7 18:54:56 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id SAA26765 for ; Wed, 7 Nov 2001 18:54:56 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 14608C69B2; Wed, 7 Nov 2001 18:53:08 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA34aWZB; Wed, 7 Nov 01 18:53:07 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id SAA17044 for tcp-impl-outgoing; Wed, 7 Nov 2001 18:43:44 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id SAA17040 for ; Wed, 7 Nov 2001 18:43:42 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id SAA02094 for ; Wed, 7 Nov 2001 18:43:42 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id DC9F8640DD; Wed, 7 Nov 2001 18:43:41 -0500 (EST) Received: from h66s122a103n47.user.nortelnetworks.com(47.103.122.66) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAA8Naaol; Wed, 7 Nov 01 18:43:41 -0500 Received: from smtprch2.nortel.com (erchg0k.us.nortel.com [47.113.64.104]) by zrc2s03g.us.nortel.com (8.9.3+Sun/8.9.1) with ESMTP id RAA28829 for ; Wed, 7 Nov 2001 17:43:39 -0600 (CST) Received: from zrchb200.us.nortel.com by smtprch2.nortel.com; Wed, 7 Nov 2001 17:36:33 -0600 Received: by zrchb200.us.nortel.com with Internet Mail Service (5.5.2653.19) id ; Wed, 7 Nov 2001 17:42:33 -0600 Message-ID: <1B54FA3A2709D51195C800508BF9386A027A5F00@zrc2c000.us.nortel.com> From: "Mehmet Yavuz" To: tcp-impl@grc.nasa.gov Subject: TCP Segment size Date: Wed, 7 Nov 2001 17:42:32 -0600 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C167E5.DE96EFD0" X-Orig: Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C167E5.DE96EFD0 Content-Type: text/plain; charset="iso-8859-1" Greetings, While running ftp tests ("put" command) with a Win95 laptop, I observe that the advertised MSS is 960Bytes both for the server and client (based on tcpdump logs). However, tcpdump logs show that during the data transfer most segments (more than 90%) are of size 512Bytes. Running "tracert" shows that between the client and server the minimum MTU size used by routers is 1500Bytes. Does anybody have an idea why a smaller segment size (512B) is used during the transfer compared to the MSS (960B)? thanks, mehmet BTW: Laptop has RS232 connection and for download tests ("get" command) mostly a segment size of 960B is observed. ------_=_NextPart_001_01C167E5.DE96EFD0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable TCP Segment size

        Greetings,

        While = running ftp tests ("put" command) with a Win95 laptop, I = observe that the advertised MSS is 960Bytes both for the server and = client (based on tcpdump logs).

        However, = tcpdump logs show that during the data transfer most segments (more = than 90%) are of size 512Bytes. Running "tracert" shows that = between the client and server the minimum MTU size used by routers is = 1500Bytes.

        Does = anybody have an idea why a smaller segment size (512B) is used during = the transfer compared to the MSS (960B)?

        thanks,
        mehmet

BTW: Laptop has RS232 connection and for download = tests ("get" command) mostly a segment size of 960B is = observed.
          =

------_=_NextPart_001_01C167E5.DE96EFD0-- From owner-tcp-impl@grc.nasa.gov Wed Nov 7 20:01:33 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id UAA27391 for ; Wed, 7 Nov 2001 20:01:33 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 4B922C692D; Wed, 7 Nov 2001 20:01:35 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAbOa4UM; Wed, 7 Nov 01 20:01:35 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id TAA24493 for tcp-impl-outgoing; Wed, 7 Nov 2001 19:52:30 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id TAA24489 for ; Wed, 7 Nov 2001 19:52:29 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id TAA05746 for ; Wed, 7 Nov 2001 19:52:28 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id AC3D8640BF; Wed, 7 Nov 2001 19:52:28 -0500 (EST) Received: from boreas.isi.edu(128.9.160.161) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAEjaq_u; Wed, 7 Nov 01 19:52:28 -0500 Received: from isi.edu (ras33.isi.edu [128.9.176.133]) by boreas.isi.edu (8.11.6/8.11.2) with ESMTP id fA80qMO18938; Wed, 7 Nov 2001 16:52:22 -0800 (PST) Message-ID: <3BE9D737.3090706@isi.edu> Date: Wed, 07 Nov 2001 16:52:07 -0800 From: Joe Touch User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.2) Gecko/20010726 Netscape6/6.1 X-Accept-Language: en-us MIME-Version: 1.0 To: Bill Fenner Cc: dovrolis@mail.eecis.udel.edu, tcp-impl@grc.nasa.gov, hjiang@mail.eecis.udel.edu Subject: Re: 3-way handshake delays References: <200111072118.NAA19703@windsor.research.att.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Bill Fenner wrote: > Some time ago, I remember seeing an idea which would cause this kind > of 3-way handshake delays. I don't remember who suggested it or where. > Basically, the idea is to only send the SYN/ACK after the first I/O is > posted to the socket (read, write, probably select). It "should" be > backwards-compatible, since programs usually do an I/O immediately after > accept(), but programs aware of the different API could, e.g., close the > connection (causing a RST, perhaps) based on IP address access control > (or some such), causing an attacker to think that the port is closed. > > I never heard of an implementation of this, but I've always thought it > was a potentially neat idea. Seems like a good way to cause a timeout. The data can't go to the application anyway; the connection doesn't exist until after the ACK comes back, so making a decision based on any connection information seems invalid, IMO. Joe From owner-tcp-impl@grc.nasa.gov Wed Nov 7 20:06:11 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id UAA27439 for ; Wed, 7 Nov 2001 20:06:11 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 47F02C6A59; Wed, 7 Nov 2001 20:04:00 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA2baiJV; Wed, 7 Nov 01 20:04:00 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id TAA24836 for tcp-impl-outgoing; Wed, 7 Nov 2001 19:58:05 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id TAA24826 for ; Wed, 7 Nov 2001 19:58:04 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id TAA05899 for ; Wed, 7 Nov 2001 19:58:01 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 5205C640F7; Wed, 7 Nov 2001 19:56:59 -0500 (EST) Received: from boreas.isi.edu(128.9.160.161) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAwnaiGv; Wed, 7 Nov 01 19:56:58 -0500 Received: from isi.edu (ras33.isi.edu [128.9.176.133]) by boreas.isi.edu (8.11.6/8.11.2) with ESMTP id fA80urO20086; Wed, 7 Nov 2001 16:56:53 -0800 (PST) Message-ID: <3BE9D846.30405@isi.edu> Date: Wed, 07 Nov 2001 16:56:38 -0800 From: Joe Touch User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.2) Gecko/20010726 Netscape6/6.1 X-Accept-Language: en-us MIME-Version: 1.0 To: Mehmet Yavuz Cc: tcp-impl@grc.nasa.gov Subject: Re: TCP Segment size References: <1B54FA3A2709D51195C800508BF9386A027A5F00@zrc2c000.us.nortel.com> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Mehmet Yavuz wrote: > > Greetings, > > While running ftp tests ("put" command) with a Win95 laptop, I > observe that the advertised MSS is 960Bytes both for the server and > client (based on tcpdump logs). > > However, tcpdump logs show that during the data transfer most > segments (more than 90%) are of size 512Bytes. Running "tracert" shows > that between the client and server the minimum MTU size used by routers > is 1500Bytes. > > Does anybody have an idea why a smaller segment size (512B) is > used during the transfer compared to the MSS (960B)? If the destination is NOT the local subnet, it is likely that the Internet MSS of 576 is used, rather than the link MTU. Presuming that path MTU is not enabled. At that point, most implementations send 512 bytes of data, rather than 536, favoring the power-of-two. > BTW: Laptop has RS232 connection and for download tests > ("get" command) mostly a segment size of 960B is observed. When the destination is the local subnet (subnet coincident with an interface), some implementations use the link MTU even if path MTU isn't enabled, assuming that the 'path' is direct. (this is in most of the TCP books, FWIW) Joe From owner-tcp-impl@grc.nasa.gov Thu Nov 8 00:40:38 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id AAA03864 for ; Thu, 8 Nov 2001 00:40:38 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id A05BEC6980; Thu, 8 Nov 2001 00:37:48 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAc3aOhX; Thu, 8 Nov 01 00:37:48 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id AAA17911 for tcp-impl-outgoing; Thu, 8 Nov 2001 00:29:50 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id AAA17907 for ; Thu, 8 Nov 2001 00:29:49 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id AAA17240 for ; Thu, 8 Nov 2001 00:29:48 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id C89F4C6927; Thu, 8 Nov 2001 00:29:11 -0500 (EST) Received: from igw3.watson.ibm.com(198.81.209.18) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAUOaOVV; Thu, 8 Nov 01 00:29:11 -0500 Received: from sp1n189at0.watson.ibm.com (sp1n189at0.watson.ibm.com [9.2.104.62]) by igw3.watson.ibm.com (8.11.4/8.11.4) with ESMTP id fA85SnR13696; Thu, 8 Nov 2001 00:28:49 -0500 Received: from orinoco.watson.ibm.com (orinoco.watson.ibm.com [9.2.16.142]) by sp1n189at0.watson.ibm.com (8.11.4/8.11.4) with ESMTP id fA85Snf112046; Thu, 8 Nov 2001 00:28:49 -0500 Received: (from nahum@localhost) by orinoco.watson.ibm.com (AIX4.3/8.9.3/8.9.3/01-10-2000) id AAA39168; Thu, 8 Nov 2001 00:28:49 -0500 From: Erich Nahum Message-Id: <200111080528.AAA39168@orinoco.watson.ibm.com> Subject: Re: 3-way handshake delays To: touch@ISI.EDU (Joe Touch) Date: Thu, 8 Nov 2001 00:28:48 -0500 (EST) Cc: fenner@research.att.com (Bill Fenner), dovrolis@mail.eecis.udel.edu, tcp-impl@grc.nasa.gov, hjiang@mail.eecis.udel.edu In-Reply-To: <3BE9D737.3090706@isi.edu> from "Joe Touch" at Nov 07, 2001 04:52:07 PM Reply-To: nahum@watson.ibm.com (Erich M. Nahum) X-Url: http://www.research.ibm.com/people/n/nahum/ X-Mailer: ELM [version 2.5 PL2] 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 Joe Touch writes: > > > Some time ago, I remember seeing an idea which would cause this kind > > of 3-way handshake delays. I don't remember who suggested it or where. > > Basically, the idea is to only send the SYN/ACK after the first I/O is > > posted to the socket (read, write, probably select). It "should" be > > backwards-compatible, since programs usually do an I/O immediately after > > accept(), but programs aware of the different API could, e.g., close the > > connection (causing a RST, perhaps) based on IP address access control > > (or some such), causing an attacker to think that the port is closed. > > > > I never heard of an implementation of this, but I've always thought it > > was a potentially neat idea. > > Seems like a good way to cause a timeout. > > The data can't go to the application anyway; the connection doesn't > exist until after the ACK comes back, so making a decision based on any > connection information seems invalid, IMO. Joe is correct. The connection can't be delivered to the application (or accept queue) until the client ACK returns for the server's SYN-ACK. I mis-understood the original question. What can happen on AIX is that the ACK of the SYN-ACK on the *client* can be delayed, hoping to piggyback on an outgoing segment (such as the first GET request) (since connect() only blocks until the SYN is ACKed). The server shouldn't deliberately delay the ACK of the SYN from the client. -Erich -- Erich M. Nahum IBM T.J. Watson Research Center Networking Research P.O. Box 704 nahum@watson.ibm.com Yorktown Heights NY 10598 From owner-tcp-impl@grc.nasa.gov Thu Nov 8 05:41:14 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id FAA21963 for ; Thu, 8 Nov 2001 05:41:14 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 3E711C69D0; Thu, 8 Nov 2001 05:40:52 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAboa4zU; Thu, 8 Nov 01 05:40:52 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id FAA07677 for tcp-impl-outgoing; Thu, 8 Nov 2001 05:28:08 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id FAA07668 for ; Thu, 8 Nov 2001 05:28:07 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id FAA05636 for ; Thu, 8 Nov 2001 05:28:06 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 22BF2640E5; Thu, 8 Nov 2001 05:27:12 -0500 (EST) Received: from unknown(202.125.87.14) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAApLaO1F; Thu, 8 Nov 01 05:27:10 -0500 Received: from sarayu.qpackets.com (machine248 [172.16.1.248]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id QAA05145 for ; Thu, 8 Nov 2001 16:01:27 +0530 Message-Id: <5.1.0.14.0.20011108155342.00a89cd0@64.170.220.2> X-Sender: srinia@64.170.220.4 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Thu, 08 Nov 2001 15:58:11 +0530 To: tcp-impl@grc.nasa.gov From: Srinivas Subject: doubt regarding the OPEN ( passive) call Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi, In RFC 793 page 45 ,[section OPEN second para] it is mentioned as :- If the active/passive flag is set to passive, then this is a call to LISTEN for an incoming connection. A PASSIVE OPEN MAY HAVE EITHER A FULLY SPECIFIED FOREIGN SOCKET TO WAIT FOR A PARTICULAR CONNECTION here comes my doubt: (pls read the above BOLD letter lines) is there any real application which gives this type of calls? i think iam clear thanks Regards, Srinivas From owner-tcp-impl@grc.nasa.gov Thu Nov 8 07:13:00 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id HAA23066 for ; Thu, 8 Nov 2001 07:13:00 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id CD5DCC694A; Thu, 8 Nov 2001 07:12:19 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA06aGBl; Thu, 8 Nov 01 07:12:19 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id HAA16156 for tcp-impl-outgoing; Thu, 8 Nov 2001 07:06:18 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id HAA16139 for ; Thu, 8 Nov 2001 07:06:16 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id HAA09201 for ; Thu, 8 Nov 2001 07:06:12 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id E2192C6949; Thu, 8 Nov 2001 07:04:17 -0500 (EST) Received: from unknown(202.125.87.14) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAI1ayQj; Thu, 8 Nov 01 07:04:15 -0500 Received: from qpackets.com (machine120 [172.16.1.120]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id RAA06349; Thu, 8 Nov 2001 17:38:22 +0530 Message-ID: <3BEA752A.2070505@qpackets.com> Date: Thu, 08 Nov 2001 17:36:02 +0530 From: Balaji Ramakrishnan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.2) Gecko/20010726 Netscape6/6.1 X-Accept-Language: en-us MIME-Version: 1.0 To: tcp-impl@egroups.com Cc: tcp-impl@grc.nasa.gov Subject: Doubt reg RFC 793 page 72 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Hi all, A basic doubt reg windows in TCP. 1. The window advt by a TCP is its receive window space. 2, From Page 72 in rfc 793 , If SND.UNA < SEG.ACK =< SND.NXT, the send window should be updated. If (SND.WL1 < SEG.SEQ or (SND.WL1 = SEG.SEQ and SND.WL2 =< SEG.ACK)), set SND.WND <- SEG.WND, set SND.WL1 <- SEG.SEQ, and set SND.WL2 <- SEG.ACK. If we start to update ur send window evrytime like this means we will be basically shrinking our send window every time we get small window advertisement.Is this correct or what is the case the above condition is valid. Pl respond and thanks in advance. Regards Balaji Ramakrishnan. From owner-tcp-impl@grc.nasa.gov Mon Nov 12 05:30:57 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id FAA24304 for ; Mon, 12 Nov 2001 05:30:57 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id B4204640D5; Mon, 12 Nov 2001 05:30:58 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAVtayNp; Mon, 12 Nov 01 05:30:58 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id FAA10703 for tcp-impl-outgoing; Mon, 12 Nov 2001 05:12:26 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id FAA10696 for ; Mon, 12 Nov 2001 05:12:25 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id FAA16226 for ; Mon, 12 Nov 2001 05:12:25 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id DBCB8640FB; Mon, 12 Nov 2001 05:01:41 -0500 (EST) Received: from unknown(202.125.87.14) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAA46aWte; Mon, 12 Nov 01 05:01:39 -0500 Received: from yahoo.com (machine120 [172.16.1.120]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id PAA02157 for ; Mon, 12 Nov 2001 15:36:03 +0530 Message-ID: <3BEF9E72.6030308@yahoo.com> Date: Mon, 12 Nov 2001 15:33:30 +0530 From: Balaji Ramakrishnan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.2) Gecko/20010726 Netscape6/6.1 X-Accept-Language: en-us MIME-Version: 1.0 To: tcp-impl Subject: Question On Retransmission timer Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Hi 1.I have one basic doubt in TCP retransmissions. What is an loss in a network ? Eg.If u are in Congestion avoidance phase and we have sent 10 segments If one segment 's RTT gets timed out.Is it a case of loss and we go to slow start. 2.Also reg SACK - SACK is used by Tx during retransmissions. Retransmisions occur 1.Due to Fast Retransmit 2.Due to Retransmission timeout also. Also in the end of RFC2018 they have specified that SACK info should be discarded when a timeout happens.(what this timeout refer to actually). Expecting some reply. Thankx in advance Balaji.R From owner-tcp-impl@grc.nasa.gov Tue Nov 13 00:30:34 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id AAA01657 for ; Tue, 13 Nov 2001 00:30:33 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 4DCCB64177; Tue, 13 Nov 2001 00:30:23 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAo4a48t; Tue, 13 Nov 01 00:30:23 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id AAA23587 for tcp-impl-outgoing; Tue, 13 Nov 2001 00:17:05 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id AAA23575 for ; Tue, 13 Nov 2001 00:17:04 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id AAA11865 for ; Tue, 13 Nov 2001 00:17:01 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id F3436C6901; Mon, 12 Nov 2001 23:47:53 -0500 (EST) Received: from unknown(202.125.87.14) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAASaaiLG; Mon, 12 Nov 01 23:47:51 -0500 Received: from sarayu.trinc.com (machine248 [172.16.1.248]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id KAA07919 for ; Tue, 13 Nov 2001 10:22:22 +0530 Message-Id: <5.1.0.14.0.20011113101353.00a92bd0@64.170.220.2> X-Sender: srinia@64.170.220.2 X-Mailer: QUALCOMM Windows Eudora Version 5.1 Date: Tue, 13 Nov 2001 10:19:15 +0530 To: tcp-impl@grc.nasa.gov From: Srinivas Amaravadi Subject: Req: Doubt regarding the MANAGING THE RTO TIMER Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii"; format=flowed Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi All, Here is a small doubt in RFC 2988 section 5.3 page4 (5.3) When an ACK is received that acknowledges new data, restart the retransmission timer so that it will expire after RTO seconds (for the current value of RTO). Why should the timer restart ??? section 5.1 and 5.2 are clear but 5.3 is not clear Thanks Srinivas From owner-tcp-impl@grc.nasa.gov Tue Nov 13 00:40:46 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id AAA01720 for ; Tue, 13 Nov 2001 00:40:45 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 2C589640C8; Tue, 13 Nov 2001 00:40:46 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAW8aq8w; Tue, 13 Nov 01 00:40:45 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id AAA24880 for tcp-impl-outgoing; Tue, 13 Nov 2001 00:30:40 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id AAA24867 for ; Tue, 13 Nov 2001 00:30:39 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id AAA12456 for ; Tue, 13 Nov 2001 00:30:37 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 8BF90640C8; Tue, 13 Nov 2001 00:28:59 -0500 (EST) Received: from iisc.ernet.in(144.16.64.3) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAJra4nt; Tue, 13 Nov 01 00:28:58 -0500 Received: from protocol.ece.iisc.ernet.in (IDENT:root@protocol.ece.iisc.ernet.in [144.16.64.120]) by iisc.ernet.in (8.9.2/8.9.0) with ESMTP id LAA08561 for ; Tue, 13 Nov 2001 11:05:44 +0530 (IST) Received: from localhost (chetan@localhost) by protocol.ece.iisc.ernet.in (8.11.0/8.11.0) with ESMTP id fAD5dCJ05750 for ; Tue, 13 Nov 2001 11:09:13 +0530 Date: Tue, 13 Nov 2001 11:09:12 +0530 (IST) From: Chetan Kumar To: tcp-impl@grc.nasa.gov Subject: test suites for TCP Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Hi, I would like to know is there any standard test suites to test TCP implementations. Thanks Chetan S From owner-tcp-impl@grc.nasa.gov Tue Nov 13 02:31:22 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id CAA17545 for ; Tue, 13 Nov 2001 02:31:21 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 24B3B640EA; Tue, 13 Nov 2001 02:31:23 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAjsaWuV; Tue, 13 Nov 01 02:31:22 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id CAA04151 for tcp-impl-outgoing; Tue, 13 Nov 2001 02:20:07 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id CAA04143 for ; Tue, 13 Nov 2001 02:20:06 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id CAA17160 for ; Tue, 13 Nov 2001 02:20:05 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id C54D1C68F4; Tue, 13 Nov 2001 02:20:04 -0500 (EST) Received: from smtp.dave.sonera.fi(131.177.130.21) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAmQay5q; Tue, 13 Nov 01 02:20:04 -0500 Received: from muuli.mv.sonera.fi ([194.137.238.208]:1433 "EHLO muuli.vallila.sonera.fi") by inside.dave.sonera.fi with ESMTP id ; Tue, 13 Nov 2001 09:19:50 +0200 Received: from laukkju1-pc (laukkju1-nb.etela.sonera.fi [131.177.251.239]) by muuli.vallila.sonera.fi (8.8.8/8.8.6) with SMTP id JAA10315 for ; Tue, 13 Nov 2001 09:16:24 +0200 (EET) From: "Andrei Gurtov" To: Subject: RE: test suites for TCP Date: Tue, 13 Nov 2001 09:17:49 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) In-Reply-To: X-MIMEOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Importance: Normal Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit > -----Original Message----- > From: owner-tcp-impl@grc.nasa.gov [mailto:owner-tcp-impl@grc.nasa.gov]On > Behalf Of Chetan Kumar > Sent: 13. marraskuuta 2001 7:39 > To: tcp-impl@grc.nasa.gov > Subject: test suites for TCP > > > Hi, > > I would like to know is there any standard test suites to test TCP > implementations. There is a number of 'fingerprinting' methods to check which TCP implementation is used, see e.g. http://www.networkice.com/Advice/Countermeasures/Scanners/Fingerprinting/def ault.htm TBIT tool by ACIRI can tell whether a given TCP uses congestion control, the size of inital window, etc. http://www.aciri.org/tbit/ However, it would be nice to have a standard test suit for a network emulator like Dummynet, Nistnet, ONE or Seawind to be able to test different TCPs by inserting a pattern of drops, delay or reodering into a connection. Andrei From owner-tcp-impl@grc.nasa.gov Tue Nov 13 02:33:51 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id CAA17561 for ; Tue, 13 Nov 2001 02:33:50 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id F28ACC6913; Tue, 13 Nov 2001 02:31:22 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAkraaxt; Tue, 13 Nov 01 02:31:22 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id CAA03929 for tcp-impl-outgoing; Tue, 13 Nov 2001 02:19:19 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id CAA03921 for ; Tue, 13 Nov 2001 02:19:17 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id CAA16999 for ; Tue, 13 Nov 2001 02:19:16 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id E952E64122; Tue, 13 Nov 2001 02:03:41 -0500 (EST) Received: from smtp.dave.sonera.fi(131.177.130.21) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAATTaqNQ; Tue, 13 Nov 01 02:03:41 -0500 Received: from muuli.mv.sonera.fi ([194.137.238.208]:1231 "EHLO muuli.vallila.sonera.fi") by inside.dave.sonera.fi with ESMTP id ; Tue, 13 Nov 2001 09:03:31 +0200 Received: from laukkju1-pc (laukkju1-nb.etela.sonera.fi [131.177.251.239]) by muuli.vallila.sonera.fi (8.8.8/8.8.6) with SMTP id JAA07942 for ; Tue, 13 Nov 2001 09:00:05 +0200 (EET) From: "Andrei Gurtov" To: Subject: RE: Doubt regarding the MANAGING THE RTO TIMER Date: Tue, 13 Nov 2001 09:01:29 +0200 Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 (Normal) X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook IMO, Build 9.0.2416 (9.0.2911.0) In-Reply-To: <5.1.0.14.0.20011113101353.00a92bd0@64.170.220.2> X-MIMEOLE: Produced By Microsoft MimeOLE V4.72.3110.3 Importance: Normal Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit > -----Original Message----- > From: owner-tcp-impl@grc.nasa.gov [mailto:owner-tcp-impl@grc.nasa.gov]On > Behalf Of Srinivas Amaravadi > Sent: 13. marraskuuta 2001 6:49 > To: tcp-impl@grc.nasa.gov > Subject: Req: Doubt regarding the MANAGING THE RTO TIMER > > > Hi All, > > Here is a small doubt in RFC 2988 section 5.3 page4 > > > (5.3) When an ACK is received that acknowledges new data, restart the > retransmission timer so that it will expire after RTO seconds > (for the current value of RTO). > > Why should the timer restart ??? section 5.1 and 5.2 are clear but 5.3 is > not clear If the timer is not restarted a spurious RTO can easily occur. Imagine the slow start phase and that the RTO value is updated once per RTT. The RTT can double between two samples due to queuing delay. If RTO is not restarted, a spurious timeout will occur before a new RTT sample is collected. More discussion can be found in: Reiner Ludwig, Keith Sklower, The Eifel Retransmission Timer. Appears in ACM Computer Communications Review, Vol. 30, No. 3, July 2000. http://iceberg.cs.berkeley.edu/publications.html In my opinion to avoid spurious RTOs TCP should collect RTT samples more frequently than once per window, and restart the timer also on fast retransmit, and possibly on partial ACKs and DUPACKs. Andrei From owner-tcp-impl@grc.nasa.gov Tue Nov 13 04:28:58 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id EAA18389 for ; Tue, 13 Nov 2001 04:28:58 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id D4252C6906; Tue, 13 Nov 2001 04:28:59 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA4ia4TX; Tue, 13 Nov 01 04:28:59 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id EAA14949 for tcp-impl-outgoing; Tue, 13 Nov 2001 04:16:34 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id EAA14828 for ; Tue, 13 Nov 2001 04:16:29 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id EAA13920 for ; Tue, 13 Nov 2001 04:16:23 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 38940C6968; Tue, 13 Nov 2001 04:12:32 -0500 (EST) Received: from colin.muc.de(193.149.48.1) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAI_aasV; Tue, 13 Nov 01 04:12:31 -0500 Received: by colin.muc.de id <140561-3>; Tue, 13 Nov 2001 10:12:55 +0100 Message-ID: <20011113101254.50970@colin.muc.de> Date: Tue, 13 Nov 2001 10:12:54 +0100 From: Andi Kleen To: Chetan Kumar Cc: tcp-impl@grc.nasa.gov Subject: Re: test suites for TCP References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii X-Mailer: Mutt 0.88e In-Reply-To: ; from Chetan Kumar on Tue, Nov 13, 2001 at 06:39:12AM +0100 Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk On Tue, Nov 13, 2001 at 06:39:12AM +0100, Chetan Kumar wrote: > Hi, > > I would like to know is there any standard test suites to test TCP > implementations. There is unfortunately no standard test suite for TCP. That is one of the reasons why it is so hard to write a good TCP. -Andi From owner-tcp-impl@grc.nasa.gov Tue Nov 13 07:43:58 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id HAA21541 for ; Tue, 13 Nov 2001 07:43:57 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 150CEC6926; Tue, 13 Nov 2001 07:43:58 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAOia4nB; Tue, 13 Nov 01 07:43:57 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id HAA00094 for tcp-impl-outgoing; Tue, 13 Nov 2001 07:30:41 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id HAA00076 for ; Tue, 13 Nov 2001 07:30:39 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id HAA20452 for ; Tue, 13 Nov 2001 07:30:38 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 6A34C640C2; Tue, 13 Nov 2001 07:27:01 -0500 (EST) Received: from uumail-relay-blr.ernet.in(202.141.1.17) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAGJa4Na; Tue, 13 Nov 01 07:19:57 -0500 Received: from protocol.ece.iisc.ernet.in (IDENT:root@protocol.ece.iisc.ernet.in [144.16.64.120]) by uumail-relay-blr.ernet.in (8.9.0/8.9.0) with ESMTP id RAA17028 for ; Tue, 13 Nov 2001 17:31:22 +0530 Received: from localhost (chetan@localhost) by protocol.ece.iisc.ernet.in (8.11.0/8.11.0) with ESMTP id fADBuwE14493; Tue, 13 Nov 2001 17:26:58 +0530 Date: Tue, 13 Nov 2001 17:26:58 +0530 (IST) From: Chetan Kumar To: Andrei Gurtov Cc: tcp-impl@grc.nasa.gov Subject: RE: test suites for TCP In-Reply-To: Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk On Tue, 13 Nov 2001, Andrei Gurtov wrote: *>> Hi, *>> I would like to know is there any standard test suites to test TCP *>> implementations. *>There is a number of 'fingerprinting' methods to check which TCP *>implementation is used, see e.g. *> *>However, it would be nice to have a standard test suit for a network Yes, I feal the same.. Just now mail Andi on the same issue (copied the same again) Just a question: Why doesn't some one write something like "standard test suite for XX protocol" make this part of standard IETF documents. Like there are various Internet protocol defined, and it is a real good idea to have a standard test suites so that it much easier for implementors to write a good inter-operable code. Especially if this is IETF document.. Thanks Chetan S *>emulator like Dummynet, Nistnet, ONE or Seawind to be able to test different *>TCPs by inserting a pattern of drops, delay or reodering into a connection. *> *>Andrei *> -- From owner-tcp-impl@grc.nasa.gov Tue Nov 13 11:46:40 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id LAA04129 for ; Tue, 13 Nov 2001 11:46:40 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 8395B640C2; Tue, 13 Nov 2001 11:46:42 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAZ6aO9t; Tue, 13 Nov 01 11:46:42 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id LAA01832 for tcp-impl-outgoing; Tue, 13 Nov 2001 11:33:42 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id LAA01822 for ; Tue, 13 Nov 2001 11:33:40 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id LAA13020 for ; Tue, 13 Nov 2001 11:33:39 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 3A415C6904; Tue, 13 Nov 2001 11:33:39 -0500 (EST) Received: from tnt.isi.edu(128.9.128.128) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAA0Payr4; Tue, 13 Nov 01 11:33:38 -0500 Received: from gra.isi.edu (gra.isi.edu [128.9.160.133]) by tnt.isi.edu (8.11.6/8.11.2) with ESMTP id fADGXWg28564; Tue, 13 Nov 2001 08:33:32 -0800 (PST) From: Bob Braden Received: (from braden@localhost) by gra.isi.edu (8.8.7/8.8.6) id QAA04067; Tue, 13 Nov 2001 16:33:32 GMT Date: Tue, 13 Nov 2001 16:33:32 GMT Message-Id: <200111131633.QAA04067@gra.isi.edu> To: chetan@protocol.ece.iisc.ernet.in, ak@muc.de Subject: Re: test suites for TCP Cc: tcp-impl@grc.nasa.gov X-Sun-Charset: US-ASCII Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk *> From owner-tcp-impl@grc.nasa.gov Tue Nov 13 01:30:31 2001 *> Date: Tue, 13 Nov 2001 10:12:54 +0100 *> From: Andi Kleen *> To: Chetan Kumar *> Cc: tcp-impl@grc.nasa.gov *> Subject: Re: test suites for TCP *> Mime-Version: 1.0 *> *> On Tue, Nov 13, 2001 at 06:39:12AM +0100, Chetan Kumar wrote: *> > Hi, *> > *> > I would like to know is there any standard test suites to test TCP *> > implementations. *> There is unfortunately no standard test suite for TCP. That is one of the *> reasons why it is so hard to write a good TCP. *> *> -Andi *> Unnnhhh, the lack of a standard test is the least of an implementor's problems!! I wrote my TCP in 1979, and I came away from the experience with a profound respect for the sublety of the protocol. Bob Braden From owner-tcp-impl@grc.nasa.gov Tue Nov 13 13:46:25 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id NAA11757 for ; Tue, 13 Nov 2001 13:46:24 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 11C11640F6; Tue, 13 Nov 2001 13:46:23 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAs_aiaj; Tue, 13 Nov 01 13:46:22 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id NAA00511 for tcp-impl-outgoing; Tue, 13 Nov 2001 13:33:27 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id NAA00463 for ; Tue, 13 Nov 2001 13:33:21 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id NAA24766 for ; Tue, 13 Nov 2001 13:33:19 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 2BCDAC6910; Tue, 13 Nov 2001 13:33:19 -0500 (EST) Received: from sj-msg-core-4.cisco.com(171.71.163.10) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAQsaGCI; Tue, 13 Nov 01 13:33:09 -0500 Received: from mira-sjcm-3.cisco.com (mira-sjcm-3.cisco.com [171.69.24.15]) by sj-msg-core-4.cisco.com (8.11.3/8.9.1) with ESMTP id fADIWrr04815; Tue, 13 Nov 2001 10:32:53 -0800 (PST) Received: from cisco.com (mbashyam-u10.cisco.com [10.34.24.166]) by mira-sjcm-3.cisco.com (Mirapoint) with ESMTP id ACO96590; Tue, 13 Nov 2001 10:19:46 -0800 (PST) Message-ID: <3BF16665.AC297DC@cisco.com> Date: Tue, 13 Nov 2001 10:28:53 -0800 From: Murali Bashyam X-Mailer: Mozilla 4.51C-CISCOENG [en] (X11; U; SunOS 5.6 sun4u) X-Accept-Language: en MIME-Version: 1.0 To: Andi Kleen Cc: Chetan Kumar , tcp-impl@grc.nasa.gov Subject: Re: test suites for TCP References: <20011113101254.50970@colin.muc.de> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit Andi Kleen wrote: > On Tue, Nov 13, 2001 at 06:39:12AM +0100, Chetan Kumar wrote: > > Hi, > > > > I would like to know is there any standard test suites to test TCP > > implementations. > There is unfortunately no standard test suite for TCP. That is one of the > reasons why it is so hard to write a good TCP. ANVL test suite from Midnight networks would be a good place to start. http://www.empirix.com/Empirix/voice+network+test/products/_anvl+faq.html. Murali > > > -Andi From owner-tcp-impl@grc.nasa.gov Tue Nov 13 15:46:14 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id PAA16218 for ; Tue, 13 Nov 2001 15:46:13 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id B1FB0640E2; Tue, 13 Nov 2001 15:42:39 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAgqaqfZ; Tue, 13 Nov 01 15:42:39 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id PAA04158 for tcp-impl-outgoing; Tue, 13 Nov 2001 15:30:14 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id PAA04139 for ; Tue, 13 Nov 2001 15:30:13 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id PAA07629 for ; Tue, 13 Nov 2001 15:30:10 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 9C649640C6; Tue, 13 Nov 2001 15:28:04 -0500 (EST) Received: from unknown(65.115.68.100) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAArNai_N; Tue, 13 Nov 01 15:28:04 -0500 Received: by mercury.corp.iready.com with Internet Mail Service (5.5.2653.19) id ; Tue, 13 Nov 2001 12:28:03 -0800 Message-ID: <639BAB6ABE61D411B3870090276A8975033323@hermes.corp.iready.com> From: Steve Potuzak To: "'tcp-impl@grc.nasa.gov'" Cc: Steve Potuzak , Robin Uyeshiro , "'mailto:gurtov@cs.Helsinki.FI'" Subject: RE: test suites for TCP Date: Tue, 13 Nov 2001 12:28:02 -0800 MIME-Version: 1.0 X-Mailer: Internet Mail Service (5.5.2653.19) Content-Type: multipart/alternative; boundary="----_=_NextPart_001_01C16C81.B1565290" Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk This message is in MIME format. Since your mail reader does not understand this format, some or all of this message may not be legible. ------_=_NextPart_001_01C16C81.B1565290 Content-Type: text/plain; charset="iso-8859-1" Hello, You might want to look into the ANVL data-network product line from Empirix.. it consists of a family of automated test suites that attempt to test, as completely as possible, against relevant RFC's (especially 793). At least some of the flexibility you mentioned concerning delay or reordering may possibly be introduced via their associated TCP development toolkit, although since I have not attempted it myself, I can't say with certainty. In any case, we are using the ANVL core TCP/IP test suite here at iReady Corporation. The following are related links.. http://www.empirix.com/empirix/voice+network+test/products/data+network+test .html http://www.empirix.com/Empirix/default.html Steven Potuzak sr. diagnostic software engineer iReady Corporation spotuzak@iready.com 808.944.5257 x21 1357 Kapiolani Blvd. Suite 102 Honolulu, HI 96814 -----Original Message----- From: Robin Uyeshiro Sent: Tuesday, November 13, 2001 8:41 AM To: Steve Potuzak Subject: FW: test suites for TCP -----Original Message----- From: Andrei Gurtov [mailto:gurtov@cs.Helsinki.FI] Sent: Monday, November 12, 2001 9:18 PM To: tcp-impl@grc.nasa.gov Subject: RE: test suites for TCP > -----Original Message----- > From: owner-tcp-impl@grc.nasa.gov [mailto:owner-tcp-impl@grc.nasa.gov]On > Behalf Of Chetan Kumar > Sent: 13. marraskuuta 2001 7:39 > To: tcp-impl@grc.nasa.gov > Subject: test suites for TCP > > > Hi, > > I would like to know is there any standard test suites to test TCP > implementations. There is a number of 'fingerprinting' methods to check which TCP implementation is used, see e.g. http://www.networkice.com/Advice/Countermeasures/Scanners/Fingerprinting/def ault.htm TBIT tool by ACIRI can tell whether a given TCP uses congestion control, the size of inital window, etc. http://www.aciri.org/tbit/ However, it would be nice to have a standard test suit for a network emulator like Dummynet, Nistnet, ONE or Seawind to be able to test different TCPs by inserting a pattern of drops, delay or reodering into a connection. Andrei ------_=_NextPart_001_01C16C81.B1565290 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable RE: test suites for TCP

Hello,

You might want to look into the ANVL data-network = product line from Empirix..
it consists of a family of automated test suites = that attempt to test,
as completely as possible, against relevant RFC's = (especially 793).
At least some of the flexibility you mentioned = concerning delay or reordering
may possibly be introduced via their associated TCP = development toolkit,
although since I have not attempted it myself, I = can't say with certainty.
In any case, we are using the ANVL core TCP/IP test = suite here at iReady Corporation.

The following are related links..

http://www.empirix.com/empirix/voice+network+test/prod= ucts/data+network+test.html

http://www.empirix.com/Empirix/default.html=


Steven Potuzak
sr. diagnostic software engineer
iReady Corporation
spotuzak@iready.com
808.944.5257 x21
1357 Kapiolani Blvd. Suite 102
Honolulu, HI 96814


-----Original Message-----
From: Robin Uyeshiro
Sent: Tuesday, November 13, 2001 8:41 AM
To: Steve Potuzak
Subject: FW: test suites for TCP




-----Original Message-----
From: Andrei Gurtov [mailto:gurtov@cs.Helsinki.FI]<= /FONT>
Sent: Monday, November 12, 2001 9:18 PM
To: tcp-impl@grc.nasa.gov
Subject: RE: test suites for TCP




> -----Original Message-----
> From: owner-tcp-impl@grc.nasa.gov [mailto:owner-tcp-impl@grc.na= sa.gov]On
> Behalf Of Chetan Kumar
> Sent: 13. marraskuuta 2001 7:39
> To: tcp-impl@grc.nasa.gov
> Subject: test suites for TCP
>
>
> Hi,
>
>       I would like to = know is there any standard test suites to test TCP
> implementations.

There is a number of 'fingerprinting' methods to = check which TCP
implementation is used, see e.g.
http://www.networkice.com/Advice/Countermeasures/Scann= ers/Fingerprinting/def
ault.htm

TBIT tool by ACIRI can tell whether a given TCP uses = congestion control, the
size of inital window, etc.
http://www.aciri.org/tbit/

However, it would be nice to have a standard test = suit for a network
emulator like Dummynet, Nistnet, ONE or Seawind to = be able to test different
TCPs by inserting a pattern of drops, delay or = reodering into a connection.

Andrei

------_=_NextPart_001_01C16C81.B1565290-- From owner-tcp-impl@grc.nasa.gov Tue Nov 13 19:20:28 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id TAA22433 for ; Tue, 13 Nov 2001 19:20:27 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id D8DC8640C3; Tue, 13 Nov 2001 19:20:28 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAQ_ay9F; Tue, 13 Nov 01 19:20:28 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id TAA12022 for tcp-impl-outgoing; Tue, 13 Nov 2001 19:00:52 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id TAA12008 for ; Tue, 13 Nov 2001 19:00:51 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id TAA03332 for ; Tue, 13 Nov 2001 19:00:49 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id 4177364158; Tue, 13 Nov 2001 18:04:54 -0500 (EST) Received: from tnt.isi.edu(128.9.128.128) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAA02aaAu; Tue, 13 Nov 01 18:04:53 -0500 Received: from gra.isi.edu (gra.isi.edu [128.9.160.133]) by tnt.isi.edu (8.11.6/8.11.2) with ESMTP id fADN4fg01929; Tue, 13 Nov 2001 15:04:41 -0800 (PST) From: Bob Braden Received: (from braden@localhost) by gra.isi.edu (8.8.7/8.8.6) id XAA04310; Tue, 13 Nov 2001 23:04:41 GMT Date: Tue, 13 Nov 2001 23:04:41 GMT Message-Id: <200111132304.XAA04310@gra.isi.edu> To: tcp-impl@grc.nasa.gov, spotuzak@corp.iready.com Subject: RE: test suites for TCP Cc: ruyeshiro@iready.com, mailto:gurtov@cs.Helsinki.FI X-Sun-Charset: US-ASCII Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk You might find RFC 1025 either a useful source or a source of amusement, depending on your viewpoint. Bob Braden From owner-tcp-impl@grc.nasa.gov Thu Nov 15 19:37:15 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id TAA29832 for ; Thu, 15 Nov 2001 19:37:15 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id A4A7064169; Thu, 15 Nov 2001 19:35:18 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAABTa40e; Thu, 15 Nov 01 19:35:18 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id TAA09756 for tcp-impl-outgoing; Thu, 15 Nov 2001 19:17:07 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id TAA09708 for ; Thu, 15 Nov 2001 19:16:59 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id TAA22185 for ; Thu, 15 Nov 2001 19:16:56 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 538C5C6939; Thu, 15 Nov 2001 19:14:22 -0500 (EST) Received: from mta05ps.bigpond.com(144.135.25.137) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAt2aOWA; Thu, 15 Nov 01 19:14:21 -0500 Received: from cvs.com.au ([144.135.25.75]) by mta05ps.bigpond.com (Netscape Messaging Server 4.15) with SMTP id GMVAAU00.BV5; Fri, 16 Nov 2001 10:20:54 +1000 Received: from ESS-p-144-138-15-231.mega.tmns.net.au ([144.138.15.231]) by PSMAM03.mailsvc.email.bigpond.com(MailRouter V2.9k 8392/4938731); 16 Nov 2001 10:14:17 Message-ID: <3BF4FC87.F9305D09@cvs.com.au> Date: Fri, 16 Nov 2001 22:46:15 +1100 From: Charles Esson Organization: Colour Vision Systems X-Mailer: Mozilla 4.77 [en] (X11; U; Linux 2.4.3-20mdk i586) X-Accept-Language: en MIME-Version: 1.0 To: Bob Braden Cc: chetan@protocol.ece.iisc.ernet.in, ak@muc.de, tcp-impl@grc.nasa.gov Subject: Re: test suites for TCP References: <200111131633.QAA04067@gra.isi.edu> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit I wrote mine in 1999 so can remember the experience reasonable well. TCP/IP may be subtle, RFC793 is a mess. I would have enormous respect for anyone who could rewrite it a tight manner. Regards Bob Braden wrote: > > *> From owner-tcp-impl@grc.nasa.gov Tue Nov 13 01:30:31 2001 > *> Date: Tue, 13 Nov 2001 10:12:54 +0100 > *> From: Andi Kleen > *> To: Chetan Kumar > *> Cc: tcp-impl@grc.nasa.gov > *> Subject: Re: test suites for TCP > *> Mime-Version: 1.0 > *> > *> On Tue, Nov 13, 2001 at 06:39:12AM +0100, Chetan Kumar wrote: > *> > Hi, > *> > > *> > I would like to know is there any standard test suites to test TCP > *> > implementations. > *> There is unfortunately no standard test suite for TCP. That is one of the > *> reasons why it is so hard to write a good TCP. > *> > *> -Andi > *> > > Unnnhhh, the lack of a standard test is the least of an implementor's > problems!! I wrote my TCP in 1979, and I came away from the experience > with a profound respect for the sublety of the protocol. > > Bob Braden From owner-tcp-impl@grc.nasa.gov Thu Nov 15 19:47:11 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id TAA00106 for ; Thu, 15 Nov 2001 19:47:11 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 708BAC6A30; Thu, 15 Nov 2001 19:45:39 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAyra4FO; Thu, 15 Nov 01 19:45:39 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id TAA11932 for tcp-impl-outgoing; Thu, 15 Nov 2001 19:37:22 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id TAA11927 for ; Thu, 15 Nov 2001 19:37:21 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id TAA23426 for ; Thu, 15 Nov 2001 19:37:17 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 9A190C691D; Thu, 15 Nov 2001 19:33:29 -0500 (EST) Received: from tnt.isi.edu(128.9.128.128) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAFda4YK; Thu, 15 Nov 01 19:33:29 -0500 Received: from gra.isi.edu (gra.isi.edu [128.9.160.133]) by tnt.isi.edu (8.11.6/8.11.2) with ESMTP id fAG0XQg29735; Thu, 15 Nov 2001 16:33:26 -0800 (PST) From: Bob Braden Received: (from braden@localhost) by gra.isi.edu (8.8.7/8.8.6) id AAA05641; Fri, 16 Nov 2001 00:33:26 GMT Date: Fri, 16 Nov 2001 00:33:26 GMT Message-Id: <200111160033.AAA05641@gra.isi.edu> To: braden@ISI.EDU, charlese@cvs.com.au Subject: Re: test suites for TCP Cc: chetan@protocol.ece.iisc.ernet.in, ak@muc.de, tcp-impl@grc.nasa.gov X-Sun-Charset: US-ASCII Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk *> From charlese@cvs.com.au Thu Nov 15 16:14:34 2001 *> Date: Fri, 16 Nov 2001 22:46:15 +1100 *> From: Charles Esson *> X-Accept-Language: en *> MIME-Version: 1.0 *> To: Bob Braden *> CC: chetan@protocol.ece.iisc.ernet.in, ak@muc.de, tcp-impl@grc.nasa.gov *> Subject: Re: test suites for TCP *> Content-Transfer-Encoding: 7bit *> *> I wrote mine in 1999 so can remember the experience reasonable well. *> TCP/IP may be subtle, RFC793 is a mess. I would have enormous respect *> for anyone who could rewrite it a tight manner. *> *> Regards *> Actually I have profound admiration for RFC 793. At the time, it was a remarkable achievement, and I believe that today very, very few protocol documents achieve the same clarity and elegance. Of course it omits many subtleties that were added later -- slow start, congestion avoidance, large windows, PAWS, SACK, ... Bob Braden From owner-tcp-impl@grc.nasa.gov Fri Nov 16 04:42:04 2001 Received: from seraph2.grc.nasa.gov (firewall-user@seraph2.lerc.nasa.gov [128.156.10.11]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id EAA25151 for ; Fri, 16 Nov 2001 04:42:03 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 71421C69BC; Fri, 16 Nov 2001 04:41:36 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAKgaGRX; Fri, 16 Nov 01 04:41:36 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id EAA28936 for tcp-impl-outgoing; Fri, 16 Nov 2001 04:32:55 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id EAA28932 for ; Fri, 16 Nov 2001 04:32:53 -0500 (EST) Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id EAA19383 for ; Fri, 16 Nov 2001 04:32:52 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id A5E0E640B6; Fri, 16 Nov 2001 04:32:52 -0500 (EST) Received: from patan.sun.com(192.18.98.43) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAATlaGFP; Fri, 16 Nov 01 04:32:52 -0500 Received: from esuncal1 ([129.147.58.119]) by patan.sun.com (8.9.3+Sun/8.9.3) with ESMTP id CAA22364 for ; Fri, 16 Nov 2001 02:32:34 -0700 (MST) Received: from xpa-fe2 ([129.147.58.119]) by esuncal1.central.sun.com (iPlanet Messaging Server 5.1 (built Sep 5 2001)) with ESMTP id <0GMV00M2CZU1BG@esuncal1.central.sun.com> for tcp-impl@grc.nasa.gov; Fri, 16 Nov 2001 02:32:25 -0700 (MST) Received: from Sun.COM ([212.238.123.153]) by mail.sun.net (iPlanet Messaging Server 5.1 (built Sep 5 2001)) with ESMTPSA id <0GMV00D0FZYGRL@mail.sun.net> for tcp-impl@grc.nasa.gov; Fri, 16 Nov 2001 02:35:08 -0700 (MST) Date: Fri, 16 Nov 2001 09:54:20 +0100 From: Henk Langeveld - NL Subject: Re: test suites for TCP To: tcp-impl@grc.nasa.gov Reply-To: tcp-impl@grc.nasa.gov Message-id: <3BF4D43C.30701@Sun.COM> Organization: IT Technology Office EMEA MIME-version: 1.0 Content-type: text/plain; charset=ISO-8859-15; format=flowed Content-transfer-encoding: 7BIT X-Accept-Language: en-us User-Agent: Mozilla/5.0 (Windows; U; Win98; en-US; rv:0.9.2) Gecko/20010726 Netscape6/6.1 (CK-anonymous) References: <200111160033.AAA05641@gra.isi.edu> Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7BIT Bob Braden wrote: > *> From: Charles Esson > *> > *> I wrote mine in 1999 so can remember the experience reasonable well. > *> TCP/IP may be subtle, RFC793 is a mess. I would have enormous respect > *> for anyone who could rewrite it a tight manner. > > Actually I have profound admiration for RFC 793. At the time, it was > a remarkable achievement, and I believe that today very, very few > protocol documents achieve the same clarity and elegance. Of course > it omits many subtleties that were added later -- slow start, > congestion avoidance, large windows, PAWS, SACK, ... A risk of test-suites in any industry is that people may start to confuse the test-suite with the standard. No test-suite can ever be exhaustive. Internet Standards require interoperability. This is why interop (and the various bake-offs[?]) was started. You need to keep coming back, and keep matching up new implementations of old and new standards and extensions to them. Henk Langeveld From owner-tcp-impl@grc.nasa.gov Wed Nov 21 16:54:16 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id QAA09762 for ; Wed, 21 Nov 2001 16:54:15 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id EDCF76410D; Wed, 21 Nov 2001 16:53:42 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAcgaGzk; Wed, 21 Nov 01 16:53:42 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id QAA26739 for tcp-impl-outgoing; Wed, 21 Nov 2001 16:33:54 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id QAA26735 for ; Wed, 21 Nov 2001 16:33:53 -0500 (EST) From: info@ltssg3.epfl.ch Received: from seraph3.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id QAA00473 for ; Wed, 21 Nov 2001 16:33:52 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id D5519640D7; Wed, 21 Nov 2001 16:33:51 -0500 (EST) Received: from pc7143.unige.ch(129.194.71.43) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAGqaG3f; Wed, 21 Nov 01 16:33:51 -0500 Received: from pc7143.unige.ch (localhost [127.0.0.1]) by pc7143.unige.ch (8.11.6/8.11.6/SuSE Linux 0.5) with ESMTP id fALMlbI26414 for ; Wed, 21 Nov 2001 23:47:37 +0100 Message-Id: <200111212247.fALMlbI26414@pc7143.unige.ch> To: tcp-impl@lerc.nasa.gov Date: Wed Nov 21 23:47:37 2001 Subject: CALL FOR PAPERS: IEEE ICME 2002, Int.Conf.MM & Expo Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk Apologies for any duplication of this announcement _____________________________________________ CALL FOR PAPERS: ICME 2002 IEEE International Conference on Multimedia and Expo Swiss Federal Institute of Technology, EPFL, Lausanne, Switzerland August 26-29 2002 GOALS OF THE CONFERENCE International Conference on Multimedia & Expo (ICME) is a major annual international conference organized with the objective of bringing together researchers, developers and practitioners from academia and industry working in all areas of multimedia. ICME serves as a forum for the dissemination of state-of-the-art research, development, and implementations of multimedia systems, technologies and applications. Co-sponsored by four IEEE societies (the Circuits and Systems Society, the Communications Society, the Computer Society and the Signal Processing Society) the third edition of ICME will be held in Lausanne, Switzerland. INSTRUCTIONS AND TOPICS Authors should submit a four-page manuscript in double-column format including authors' names, affiliations and a short abstract. Only electronic submission will be accepted. A sample of the papers presented at the conference will be selected for a possible publication in an upcoming special issue of IEEE Transactions on Multimedia. Topics covered include but are not limited to the following: * Audio, image and/or video processing * Components and technologies for multimedia systems * Human-machine interface and interaction * Multimedia applications * Multimedia hardware architectures * Multimedia communication and networking * Multimedia computing systems * Multimedia content access and distribution * Multimedia databases * Signal processing for media integration * Standards (e.g., MPEG) and related issues * System integration, integration of art and technologies * Virtual reality and computer graphics * Watermarking and security CONFERENCE WEB SITE AND CONTACT Web: http://www.icme2002.org Contact: info@icme02.epfl.ch SPECIAL SESSIONS, TUTORIALS, DEMO/EXHIBITS Proposals for Special Sessions, Tutorials and Demo/Exhibits are also strongly encouraged. Authors are referred to the ICME website to additional information regarding submissions. IMPORTANT DATES Special Session Proposal Due December 1, 2001 Regular Papers Submission Due February 15, 2002 Tutorial Proposal Due March 1, 2002 Demo/Exhibit Proposal Due May 1, 2002 Thierry Pun, Univ. of Geneva, Switzerland Jean-Luc Dugelay, Eurecom, France ICME Publicity co-Chairs PS: feel free to distribute! ----------------------------------------------------------------------- To subscribe the ICME 2002 information mailing list, e-mail icme2002-request@ltssg3.epfl.ch with "subscribe" in the body. ----------------------------------------------------------------------- From owner-tcp-impl@grc.nasa.gov Mon Nov 26 04:25:24 2001 Received: from seraph3.grc.nasa.gov (firewall-user@seraph3.lerc.nasa.gov [128.156.10.12]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id EAA17979 for ; Mon, 26 Nov 2001 04:25:24 -0500 (EST) Received: by seraph3.grc.nasa.gov (Postfix, from userid 5) id B000A640B7; Mon, 26 Nov 2001 04:25:20 -0500 (EST) Received: from lombok-fi.lerc.nasa.gov(139.88.112.33) by seraph3.grc.nasa.gov via csmap (V6.0) id srcAAAFyaWgq; Mon, 26 Nov 01 04:25:20 -0500 Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id EAA04461 for tcp-impl-outgoing; Mon, 26 Nov 2001 04:11:38 -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 LeRC 8.9.1.1/8.9.1) with ESMTP id EAA04457 for ; Mon, 26 Nov 2001 04:11:37 -0500 (EST) Received: from seraph2.grc.nasa.gov (localhost [127.0.0.1]) by acs-viruswall.grc.nasa.gov (NASA LeRC 8.9.1.1/8.11.x) with ESMTP id EAA18831 for ; Mon, 26 Nov 2001 04:11:36 -0500 (EST) Received: by seraph2.grc.nasa.gov (Postfix, from userid 5) id 76A6CC68E4; Mon, 26 Nov 2001 04:11:35 -0500 (EST) Received: from unknown(202.125.87.14) by seraph2.grc.nasa.gov via csmap (V6.0) id srcAAAsEaG9S; Mon, 26 Nov 01 04:11:33 -0500 Received: from qpackets.com (machine120 [172.16.1.120]) by brahma.roc.com (8.9.3/8.8.7) with ESMTP id OAA27965 for ; Mon, 26 Nov 2001 14:45:13 +0530 Message-ID: <3C02076F.3070608@qpackets.com> Date: Mon, 26 Nov 2001 14:42:15 +0530 From: Balaji Ramakrishnan User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.0; en-US; rv:0.9.2) Gecko/20010726 Netscape6/6.1 X-Accept-Language: en-us MIME-Version: 1.0 To: tcp-impl Subject: Duplicate Ack implementation Content-Type: multipart/alternative; boundary="------------070703060306010304060204" Sender: owner-tcp-impl@grc.nasa.gov Precedence: bulk --------------070703060306010304060204 Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Hi all, In the implementation of fast retransmit algorithm we check receipt of duplicate acks. Q1.So whenever a receiver ou-of order in-sequence segment it should send a Duplicate ACK segment immediately. So can data accompany this duplicate Ack segment. Q2. If data accompanies a ACK response for out -of -segment then how to differentiate between the normal transmission of segments where the RCV.nxt is copied as Ack i.e we are just transmitting but no segments we received. Q3.Is there any RFC which says what an duplicate ack segment should contain for receipt of out-of -order segment or it is implementation specific. Thankx in advance Regards Balaji.R --------------070703060306010304060204 Content-Type: text/html; charset=us-ascii Content-Transfer-Encoding: 7bit Hi all,
      In the implementation of fast retransmit algorithm we check receipt of
      duplicate acks.

 Q1.So whenever a receiver ou-of order in-sequence segment
       it should send a Duplicate ACK segment immediately.
       So can data accompany this duplicate Ack segment.
 
Q2. If data accompanies a ACK response for out -of -segment then
      how to differentiate between the normal transmission of segments
     where the RCV.nxt is copied as Ack
     i.e we are just transmitting but no segments we received.
 
Q3.Is there any RFC which says what an duplicate ack segment should contain
      for receipt of out-of -order segment or it is implementation specific.

Thankx in advance
Regards
Balaji.R
   

     

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