From owner-freebsd-net@FreeBSD.ORG Thu Dec 7 12:13:03 2006 Return-Path: X-Original-To: freebsd-net@freebsd.org Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [69.147.83.52]) by hub.freebsd.org (Postfix) with ESMTP id 2D5E516A49E for ; Thu, 7 Dec 2006 12:13:03 +0000 (UTC) (envelope-from rrs@cisco.com) Received: from sj-iport-4.cisco.com (sj-iport-4.cisco.com [171.68.10.86]) by mx1.FreeBSD.org (Postfix) with ESMTP id 427A743CA2 for ; Thu, 7 Dec 2006 12:12:11 +0000 (GMT) (envelope-from rrs@cisco.com) Received: from sj-dkim-6.cisco.com ([171.68.10.81]) by sj-iport-4.cisco.com with ESMTP; 07 Dec 2006 04:13:02 -0800 Received: from sj-core-4.cisco.com (sj-core-4.cisco.com [171.68.223.138]) by sj-dkim-6.cisco.com (8.12.11/8.12.11) with ESMTP id kB7CD20Z013887; Thu, 7 Dec 2006 04:13:02 -0800 Received: from xbh-sjc-221.amer.cisco.com (xbh-sjc-221.cisco.com [128.107.191.63]) by sj-core-4.cisco.com (8.12.10/8.12.6) with ESMTP id kB7CD0OV013995; Thu, 7 Dec 2006 04:13:00 -0800 (PST) Received: from xfe-sjc-211.amer.cisco.com ([171.70.151.174]) by xbh-sjc-221.amer.cisco.com with Microsoft SMTPSVC(6.0.3790.1830); Thu, 7 Dec 2006 04:12:58 -0800 Received: from [127.0.0.1] ([171.68.225.134]) by xfe-sjc-211.amer.cisco.com with Microsoft SMTPSVC(6.0.3790.1830); Thu, 7 Dec 2006 04:12:57 -0800 Message-ID: <45780519.6050207@cisco.com> Date: Thu, 07 Dec 2006 07:12:09 -0500 From: Randall Stewart User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.7.12) Gecko/20050920 X-Accept-Language: en-us, en MIME-Version: 1.0 To: Ivo Vachkov References: <161d69110612060709n3bf99bd4y47d94b021b8f1d02@mail.gmail.com> <4577D858.4010300@freebsd.org> <2786D1DE-E8FA-490C-AFF7-E458E262AEF7@lurchi.franken.de> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 07 Dec 2006 12:12:57.0777 (UTC) FILETIME=[08287A10:01C719F9] DKIM-Signature: v=0.5; a=rsa-sha256; q=dns/txt; l=1662; t=1165493582; x=1166357582; c=relaxed/simple; s=sjdkim6002; h=Content-Type:From:Subject:Content-Transfer-Encoding:MIME-Version; d=cisco.com; i=rrs@cisco.com; z=From:=20Randall=20Stewart=20 |Subject:=20Re=3A=20Urel, =20a=20TCP=20option=20for=20Unreliable=20Streami ng.=20Need=20your=20help. |Sender:=20; bh=R0nbJ4HHRSh+jwEHuTUfC6mWqUUbvcnAdpDAweht8b0=; b=BFL8WNEl6FH3JZmK7sMDrq6fqSvLXnMQGSvWnvISlm3qgnZc8q/K2YkJ7zYCgDIr+s5E7w0i JSfrq62a1AnMyDZFA8PxGNbRKYyZqSURt+WB408+7N58rShDZ1nLNfvj; Authentication-Results: sj-dkim-6; header.From=rrs@cisco.com; dkim=pass (sig from cisco.com/sjdkim6002 verified; ); Cc: Michael Tuexen , freebsd-net@freebsd.org Subject: Re: Urel, a TCP option for Unreliable Streaming. Need your help. X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 07 Dec 2006 12:13:03 -0000 Ivo Vachkov wrote: > On 12/7/06, Michael Tuexen wrote: > >> >> Hi Andre, >> >> see my comments in-line. >> >> Best regards >> Michael >> >> >> SCTP has a extension called PR-SCTP, which is implemented in BSD >> and can be used to limit the number of retransmissions of a >> DATA chunk to 0. The service you mention above is therefore available >> in SCTP. > > > > > There is only one problem with that - you need to do a major rewrite of > your > current software to use SCTP No, I disagree here.. we designed the API of SCTP to literally be completely compatible with TCP.. You do sd = socket(AF_INET, SOCK_STREAM, 0); change this to sd = socket(AF_INET, SOCK_STREAM, IPPROTO_SCTP); and you now have SCTP .. if you use a socket option or two (no delay for example) you will have to change this to the SCTP equivlant.. which are conviently named the smae with SCTP_ at the prefix... There is also a shim layer that makes it so you can do both TCP and SCTP (trying SCTP first).. but thats not ready yet.. ;-) and hope that all OSs it's supposed to run > on/with have SCTP support (and it's enabled). Ahh.. well there is that.. all O/S's (current ones at least) support SCTP with the exception of WinDoz.. You can add a package to WinDoz to make SCTP run on it.. but no one likes to do that :-) And besides.. if you are doing partial reliable TCP do you really think you can do it without both ends supporting it? The same problem would exist here.. R > -- Randall Stewart NSSTG - Cisco Systems Inc. 803-345-0369 803-317-4952 (cell)