From owner-tcp-impl@lerc.nasa.gov Mon Aug 30 10:19:57 1999 Received: from lombok-fi.lerc.nasa.gov (lombok-fi.lerc.nasa.gov [139.88.112.33]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id KAA01327 for ; Mon, 30 Aug 1999 10:19:56 -0400 (EDT) Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id HAA06292 for tcp-impl-outgoing; Mon, 30 Aug 1999 07:03:35 -0400 (EDT) Received: from ietf.org (fw01.lerc.nasa.gov [139.88.145.14]) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) with ESMTP id HAA06288 for ; Mon, 30 Aug 1999 07:03:33 -0400 (EDT) Received: from CNRI.Reston.VA.US (localhost [127.0.0.1]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id HAA19879; Mon, 30 Aug 1999 07:03:30 -0400 (EDT) Message-Id: <199908301103.HAA19879@ietf.org> Mime-Version: 1.0 Content-Type: Multipart/Mixed; Boundary="NextPart" To: IETF-Announce: ; Cc: tcp-impl@grc.nasa.gov From: Internet-Drafts@ietf.org Reply-to: Internet-Drafts@ietf.org Subject: I-D ACTION:draft-ietf-tcpimpl-pmtud-02.txt Date: Mon, 30 Aug 1999 07:03:29 -0400 Sender: owner-tcp-impl@lerc.nasa.gov Precedence: bulk --NextPart A New Internet-Draft is available from the on-line Internet-Drafts directories. This draft is a work item of the TCP Implementation Working Group of the IETF. Title : TCP Problems with Path MTU Discovery Author(s) : K. Lahey Filename : draft-ietf-tcpimpl-pmtud-02.txt Pages : 15 Date : 27-Aug-99 This memo catalogs several known TCP implementation problems dealing with Path MTU Discovery [RFC1191], including the long-standing black hole problem, stretch ACKs due to confusion between MSS and segment size, and MSS advertisement based on PMTU. The goal in doing so is to improve conditions in the existing Internet by enhancing the quality of current TCP/IP implementations. A URL for this Internet-Draft is: http://www.ietf.org/internet-drafts/draft-ietf-tcpimpl-pmtud-02.txt Internet-Drafts are also available by anonymous FTP. Login with the username "anonymous" and a password of your e-mail address. After logging in, type "cd internet-drafts" and then "get draft-ietf-tcpimpl-pmtud-02.txt". A list of Internet-Drafts directories can be found in http://www.ietf.org/shadow.html or ftp://ftp.ietf.org/ietf/1shadow-sites.txt Internet-Drafts can also be obtained by e-mail. Send a message to: mailserv@ietf.org. In the body type: "FILE /internet-drafts/draft-ietf-tcpimpl-pmtud-02.txt". NOTE: The mail server at ietf.org can return the document in MIME-encoded form by using the "mpack" utility. To use this feature, insert the command "ENCODING mime" before the "FILE" command. To decode the response(s), you will need "munpack" or a MIME-compliant mail reader. Different MIME-compliant mail readers exhibit different behavior, especially when dealing with "multipart" MIME messages (i.e. documents which have been split up into multiple messages), so check your local documentation on how to manipulate these messages. Below is the data which will enable a MIME compliant mail reader implementation to automatically retrieve the ASCII version of the Internet-Draft. --NextPart Content-Type: Multipart/Alternative; Boundary="OtherAccess" --OtherAccess Content-Type: Message/External-body; access-type="mail-server"; server="mailserv@ietf.org" Content-Type: text/plain Content-ID: <19990827101735.I-D@ietf.org> ENCODING mime FILE /internet-drafts/draft-ietf-tcpimpl-pmtud-02.txt --OtherAccess Content-Type: Message/External-body; name="draft-ietf-tcpimpl-pmtud-02.txt"; site="ftp.ietf.org"; access-type="anon-ftp"; directory="internet-drafts" Content-Type: text/plain Content-ID: <19990827101735.I-D@ietf.org> --OtherAccess-- --NextPart-- From owner-tcp-impl@lerc.nasa.gov Mon Aug 30 17:19:53 1999 Received: from lombok-fi.lerc.nasa.gov (lombok-fi.lerc.nasa.gov [139.88.112.33]) by ietf.org (8.9.1a/8.9.1a) with ESMTP id RAA15703 for ; Mon, 30 Aug 1999 17:19:48 -0400 (EDT) Received: (from listserv@localhost) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) id OAA26778 for tcp-impl-outgoing; Mon, 30 Aug 1999 14:29:35 -0400 (EDT) Received: from jp1.dot.net.in (fw01.lerc.nasa.gov [139.88.145.14]) by lombok-fi.lerc.nasa.gov (NASA LeRC 8.9.1.1/8.9.1) with SMTP id OAA26760 for ; Mon, 30 Aug 1999 14:29:26 -0400 (EDT) Received: from [210.212.96.127] by jp1.dot.net.in; (5.65v3.2/1.1.8.2/10Nov98-1112AM) id AA32123; Tue, 31 Aug 1999 00:11:12 GMT Message-Id: <001201bef314$bc760820$7f60d4d2@Shivani> From: "Aniruddh Lohia" To: Subject: A question?? Date: Mon, 30 Aug 1999 23:53:02 +0530 Mime-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit X-Priority: 3 X-Msmail-Priority: Normal X-Mailer: Microsoft Outlook Express 4.72.3110.1 X-Mimeole: Produced By Microsoft MimeOLE V4.72.3110.3 Sender: owner-tcp-impl@lerc.nasa.gov Precedence: bulk Content-Transfer-Encoding: 7bit I have a question to ask from you. Why is the question of connection oriented and connectionless service raised three times i.e. in the Datalink Layer, Network Layer and Transport Layer. three of the layers have this time-out & retransmission facility. There is one point that DataLink layer is in hardware and Network Layer may or may not be in hardware that is why we use in Transport layer(which is s/w implemented) but using it thrice is weired. Also boss consider that all three layers i.e. DataLink, Network & Transport have this connection oriented method with time out of say 50ms, 55ms & 60 ms respectively. Suppose no acknowledgement comes till 63 ms second within which period all the three layers have retransmitted THRICE thus contributing significantly to congestion. Aniruddh