From owner-freebsd-net@FreeBSD.ORG Mon Mar 7 16:39:51 2005 Return-Path: Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id D7B5016A4CE for ; Mon, 7 Mar 2005 16:39:51 +0000 (GMT) Received: from mxsf28.cluster1.charter.net (mxsf28.cluster1.charter.net [209.225.28.228]) by mx1.FreeBSD.org (Postfix) with ESMTP id 6573943D5A for ; Mon, 7 Mar 2005 16:39:51 +0000 (GMT) (envelope-from c0ldbyte@myrealbox.com) Received: from mxip12.cluster1.charter.net (mxip12a.cluster1.charter.net [209.225.28.142])j27Gdok8025554 for ; Mon, 7 Mar 2005 11:39:50 -0500 Received: from 24.247.253.134.gha.mi.chartermi.net (HELO eleanor.us1.wmi.uvac.net) (24.247.253.134) by mxip12.cluster1.charter.net with ESMTP; 07 Mar 2005 11:39:50 -0500 X-Ironport-AV: i="3.90,143,1107752400"; d="scan'208"; a="859461029:sNHT12443616" Date: Mon, 7 Mar 2005 11:39:46 -0500 (EST) From: c0ldbyte To: Noritoshi Demizu In-Reply-To: <20050308.001714.41652371.Noritoshi@Demizu.ORG> Message-ID: <20050307113917.V15707@eleanor.us1.wmi.uvac.net> References: <20050308.001714.41652371.Noritoshi@Demizu.ORG> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII; format=flowed cc: freebsd-net@freebsd.org Subject: Re: Why TCP_MAX_SACK == 3 ? X-BeenThere: freebsd-net@freebsd.org X-Mailman-Version: 2.1.1 Precedence: list List-Id: Networking and TCP/IP with FreeBSD List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 07 Mar 2005 16:39:52 -0000 -----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 On Tue, 8 Mar 2005, Noritoshi Demizu wrote: > In netinet/tcp.h, TCP_MAX_SACK is defined as follows. > > #define TCP_MAX_SACK 3 /* MAX # SACKs sent in any segment */ > > Shouldn't it be 4? If a peer node does not use TCP timestamps option, > four SACK blocks can be sent. For example, if my memory serves correctly, > Microsoft Windows does not use TCP timestamps option by default. > > > By the way, currently, both window scale option and timestamps option > are controled by one sysctl variable: net.inet.tcp.rfc1323. > Wouldn't it be nice if each option had its own sysctl variable? > > Regards, > Noritoshi Demizu As Im showing in my source tree for 4.11 \ #define TCPOPT_SACK_PERMITTED 4 /* Experimental */ #define TCPOLEN_SACK_PERMITTED 2 #define TCPOPT_SACK 5 /* Experimental */ -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.0 (FreeBSD) Comment: http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xF7DF979F iD8DBQFCLIPVsmFQuvffl58RAg6ZAJ93OjZxUnjzmzVDFCsYV6vF1VSRbwCcDeTL 0Lk/WpovPFMPV9c3thb/FPY= =wKZs -----END PGP SIGNATURE-----