From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: Re: IP/UDP encapsulation Date: Thu, 08 Apr 2010 12:29:33 +0200 Message-ID: <1270722573.2215.47.camel@edumazet-laptop> References: <20100408074247.GA19798@vigoh> <20100408191831.08cd8d7b@opy.nosense.org> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: "Gustavo F. Padovan" , netdev@vger.kernel.org, marco bonola , "ZioPRoTo (Saverio Proto)" , Behling Mario , "L. Aaron Kaplan" To: Mark Smith Return-path: Received: from mail-bw0-f209.google.com ([209.85.218.209]:60007 "EHLO mail-bw0-f209.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751410Ab0DHK3j (ORCPT ); Thu, 8 Apr 2010 06:29:39 -0400 Received: by bwz1 with SMTP id 1so1647463bwz.21 for ; Thu, 08 Apr 2010 03:29:36 -0700 (PDT) In-Reply-To: <20100408191831.08cd8d7b@opy.nosense.org> Sender: netdev-owner@vger.kernel.org List-ID: Le jeudi 08 avril 2010 =C3=A0 19:18 +0930, Mark Smith a =C3=A9crit : > On Thu, 8 Apr 2010 04:42:47 -0300 > "Gustavo F. Padovan" wrote: >=20 > > Hi, > >=20 > > I'm looking for some advice on that work. The Freifunk organization= is > > planning work on the IP/UDP encapsulation kernel module as a GSoC > > project. The idea is to create a IP-in-UDP tunnel like we do for > > IP-in-IP or IP-in-GRE tunnels. The only way to do that today is to = use > > some VPN software. > >=20 > > The module will export its virtual interface through sockets and wi= ll > > have support for the standard syscalls like the others encapsulatio= n > > modules. > >=20 > > It will improve the performance of mesh networks that will we be ab= le > > to use IP-in-UDP rather than IP-in-IP. >=20 > I'm a bit confused. How can tunnelling IP in UDP in IP be faster than= IP in IP? >=20 Maybe the 'gateway' doesnt handle IPIP at all ;) Until 2.6.32, IPIP tunnels were not so scalable then UDP (RCU enabled) ipip_rcv() was hitting a global rwlock git describe 8f95dd63a2ab6fe7243c4f0bd2c3266e3a5525ab v2.6.32-rc3-468-g8f95dd6