From owner-freebsd-current Fri Jan 22 07:24:29 1999 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id HAA28302 for freebsd-current-outgoing; Fri, 22 Jan 1999 07:24:29 -0800 (PST) (envelope-from owner-freebsd-current@FreeBSD.ORG) Received: from apollo.sitaranetworks.com (apollo.sitaranetworks.com [199.103.141.105]) by hub.freebsd.org (8.8.8/8.8.8) with SMTP id HAA28235 for ; Fri, 22 Jan 1999 07:24:26 -0800 (PST) (envelope-from loverso@sitara.net) Received: from sitara.net (jamaica.sitaranetworks.com [199.103.141.147]) by apollo.sitaranetworks.com (8.9.1a/8.9.1) with ESMTP id KAA05863; Fri, 22 Jan 1999 10:09:32 -0500 (EST) Message-ID: <36A89597.98108990@sitara.net> Date: Fri, 22 Jan 1999 10:13:27 -0500 From: "John R. LoVerso" Reply-To: loverso@sitaranetworks.com Organization: Sitara Networks, http://surf.to/loverso/ X-Mailer: Mozilla 4.5 [en] (WinNT; I) X-Accept-Language: en MIME-Version: 1.0 To: Konstantin Chuguev CC: freebsd-current@FreeBSD.ORG Subject: Re: T/TCP in FreeBSD-3.x References: <36A85EF1.444A86B@urc.ac.ru> Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > Why I'm asking about this, is because I recently read an advice in one > of the FreeBSD mailing lists, > about "Why my dial-up PPP connection from a FreeBSD box is so slow > comparing with Windows NT > (about ten times slower)?" > > And the advice was (without explanations): "Try to switch off the > TCP_EXTENSIONS in /etc/rc.conf". This isn't something that can be fixed in FreeBSD's TCP. Rather, it is a general bug in how TCP Header Compression is defined for PPP and SLIP. Basically, TCP Header Compression will not compress any TCP segment that contains a TCP option. This means the use of ANY TCP option, whether T/TCP or RTTM, will cause your PPP links to not compress those packets and, thus, make your link slower. Unfortunately, just fixing FreeBSD isn't the answer, because you need to fix EVERY implementation of PPP to accept and generate TCP segments with options. The new "IP Header Compression" Internet Draft specifies how this is to be done. John To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message