From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Leblond Subject: Re: bandwidth saving idea Date: Mon, 11 Jul 2005 15:26:34 +0200 Message-ID: <1121088394.26639.8.camel@localhost.localdomain> References: <20050701004115.34697.qmail@web26507.mail.ukl.yahoo.com> <42C853F4.6010702@outerspace.dyndns.org> <1121087802.4967.35.camel@OSCARLAPLIN> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15 Content-Transfer-Encoding: quoted-printable Cc: netfilter-devel@lists.netfilter.org Return-path: To: oscar@ufomechanic.net In-Reply-To: <1121087802.4967.35.camel@OSCARLAPLIN> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: netfilter-devel-bounces@lists.netfilter.org Errors-To: netfilter-devel-bounces@lists.netfilter.org List-Id: netfilter-devel.vger.kernel.org Le lundi 11 juillet 2005 =E0 14:16 +0100, Oscar Mechanic a =E9crit : > Machine A sends a packet to machine B. As the packet passes through > If the same packet is sent again through A it does not send the payload > to Machine B but sends the checksum. B sees the checksum finds the > payload and replaces the checksum with the payload. Well, there's a problem with protocol like TCP, you've got SEQ number and other flags in TCP header that are changing even if the datas contained in the packet are the same. Thus your compression protocol is not efficient. Even a 1000 unit FIFO is useless. Furthermore, your protocol is theoritically wrong, as checksum functions are not injective. You better try to set up an ipsec tunnel with compression between the two machines. On protocol other than citrix, this can bring you a good compression level (30% or more if I recall correctly some tests I've made). BR, --=20 Eric Leblond