From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-23-ewr.dyndns.com (mxout-043-ewr.mailhop.org [216.146.33.43]) by lists.bufferbloat.net (Postfix) with ESMTP id A47C52E020F for ; Wed, 16 Feb 2011 15:51:13 -0800 (PST) Received: from scan-22-ewr.mailhop.org (scan-22-ewr.local [10.0.141.244]) by mail-23-ewr.dyndns.com (Postfix) with ESMTP id 283FF4121D for ; Wed, 16 Feb 2011 23:51:13 +0000 (UTC) X-Spam-Score: 0.1 () X-Mail-Handler: MailHop by DynDNS X-Originating-IP: 75.145.127.229 Received: from gw.co.teklibre.org (75-145-127-229-Colorado.hfc.comcastbusiness.net [75.145.127.229]) by mail-23-ewr.dyndns.com (Postfix) with ESMTP id 225C9400DD for ; Wed, 16 Feb 2011 23:51:09 +0000 (UTC) Received: from cruithne.co.teklibre.org (unknown [IPv6:2002:4b91:7fe5:2:21c:25ff:fe80:46f9]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client CN "cruithne.co.teklibre.org", Issuer "CA Cert Signing Authority" (verified OK)) by gw.co.teklibre.org (Postfix) with ESMTPS id 63E185EF5A for ; Wed, 16 Feb 2011 16:51:08 -0700 (MST) Received: by cruithne.co.teklibre.org (Postfix, from userid 1000) id B53C5121B0D; Wed, 16 Feb 2011 16:51:07 -0700 (MST) From: d@taht.net (Dave =?utf-8?Q?T=C3=A4ht?=) To: Jesper Louis Andersen Organization: Teklibre - http://www.teklibre.com References: <20110216174627.GA20215@brevard.conman.org> <6F4E15F3B5314030A7C34DCC49395D8B@srichardlxp2> Date: Wed, 16 Feb 2011 16:51:07 -0700 In-Reply-To: (Jesper Louis Andersen's message of "Thu, 17 Feb 2011 00:34:39 +0100") Message-ID: <87r5b7iln8.fsf@cruithne.co.teklibre.org> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Cc: bloat@lists.bufferbloat.net Subject: Re: [Bloat] Background Bufferbloat Detector X-BeenThere: bloat@lists.bufferbloat.net X-Mailman-Version: 2.1.13 Precedence: list List-Id: General list for discussing Bufferbloat List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Wed, 16 Feb 2011 23:51:13 -0000 Jesper Louis Andersen writes: > On Wed, Feb 16, 2011 at 20:03, Richard Scheffenegger wro= te: >> >> Perhaps Bittorrent Clients can be used to export the one-way delay, as >> measured by the =C2=B5TP protocol, to build an complementary background >> bufferbloat detector [..] >> >> And, hosting legal content on one's own Bittorrent Client should provide >> ample opportunity to get decent measurements, without the need to negoti= ate >> with someone else about taking readings off some debug-log from an NTP >> server.... >> > > The only "slight" problem is that not all clients support =C2=B5TP. You a= re > limited to hacking either KTorrent 4.0+ (C++) or Vuze (Java). There > are C clients in progression however (Transmission, libtorrent). My > "own" client (in Erlang) has been putting off the implementation, > mostly because I'd rather see TCP fixed :) But perhaps this could be a > good opportunity to just hack up that protocol :) > > BitTorrent also has the advantage that it often connects to hosts from > all over the world, so if there is any indication in the data, it > should definitely be able to see a trend. This is one of the coolest applications of bittorrent technology I've ever heard of.=20 I was basically going through /etc/services, and /etc/protocols while thinking about this. I thought DNS might be an answer but it didn't contain enough information... Snmp data contains a MIB that ostensibly reports on queue size, but no time related info... I only got as far as port 123 (NTP) which thus far seems a win. The progress over on comp.protocols.time.ntp is also promising... A problem in using bittorrent is in reporting, in that a bufferbloat detecting torrent client or server would have to phone home somehow. On the other hand, that could also be interestingly anonymized[1] /me girds up to get through the remaining protocols - I am stopped at port 179 right now, thinking hard.... --=20 Dave Taht http://nex-6.taht.net 1: (Bt the solution is too long to fit into the margins of this email)