From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from plane.gmane.org (plane.gmane.org [80.91.229.3]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 6EAE021F0F0 for ; Tue, 27 Nov 2012 16:51:27 -0800 (PST) Received: from list by plane.gmane.org with local (Exim 4.69) (envelope-from ) id 1TdVsE-0001jQ-LD for bloat@lists.bufferbloat.net; Wed, 28 Nov 2012 01:51:34 +0100 Received: from 1809ds4-ro.0.fullrate.dk ([90.184.46.60]) by main.gmane.org with esmtp (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 28 Nov 2012 01:51:34 +0100 Received: from toke by 1809ds4-ro.0.fullrate.dk with local (Gmexim 0.1 (Debian)) id 1AlnuQ-0007hv-00 for ; Wed, 28 Nov 2012 01:51:34 +0100 X-Injected-Via-Gmane: http://gmane.org/ To: bloat@lists.bufferbloat.net From: =?utf-8?Q?Toke_H=C3=B8iland-J=C3=B8rgensen?= Date: Wed, 28 Nov 2012 01:51:05 +0100 Message-ID: <87d2yymtxi.fsf@toke.dk> References: <20121123221842.GD2829@linux.vnet.ibm.com> <87a9u7amon.fsf@toke.dk> <87txscm2lm.fsf@toke.dk> <87obiklzm4.fsf@toke.dk> <1353973198.619924429@apps.rackspace.com> <87ip8rncg5.fsf@toke.dk> <50B4ED31.9000103@net.t-labs.tu-berlin.de> Mime-Version: 1.0 Content-Type: multipart/signed; boundary="=-=-="; micalg=pgp-sha256; protocol="application/pgp-signature" X-Complaints-To: usenet@ger.gmane.org X-Gmane-NNTP-Posting-Host: 1809ds4-ro.0.fullrate.dk User-Agent: Gnus/5.130006 (Ma Gnus v0.6) Emacs/24.2 (gnu/linux) Cancel-Lock: sha1:7F3ls3LU1+0OJ/EeSuzvhfS0W9A= Subject: Re: [Bloat] [Cerowrt-devel] FQ_Codel lwn draft article review 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, 28 Nov 2012 00:51:27 -0000 --=-=-= Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Oliver Hohlfeld writes: > The jitter measurements you have in mind will give you an idea on the > jitter specific to the chosen traffic scenario, nothing more --- and > in particular not the VoIP quality (although low vs. high jitter could > /indicate/ certain /possible/ quality degradations). Well no, in this sense the only "real" test for voip quality is picking up the (soft)phone and talking to someone. However, since the context here is automated measuring tools (preferably generating solid quantitative, comparable data), that is hardly feasible. I guess the goal of a comprehensive testing suite is to gather as many indicators of quality degradations (in the widest possible sense) as possible and testing for them under a variety of traffic conditions. I am by no means an expert on VoIP, but someone suggested measuring jitter could be useful, and I've proposed a possible way to do that (using iperf udp flows at a low-ish bandwidth). Since for the purpose of this particular discussion I seem to be in the test tool building business (at least for the time being), what I really need before going forward with this is someone to comment on (a) if using iperf udp flows is a valid way to measure jitter, (b) if measuring jitter is actually something someone wants to do and (c) if there are other tests that would be useful for testing VoIP (or general) conditions instead of / in addition to the jitter measurements. So far I don't have an answer to (a), only negative answers to (b) and nothing concrete for (c). So for the time being I'm shelving the idea, and will just note that it seems quite feasible to return to it should someone change their mind on (b) :) =2DToke =2D-=20 Toke H=C3=B8iland-J=C3=B8rgensen toke@toke.dk --=-=-= Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.19 (GNU/Linux) iQEcBAEBCAAGBQJQtV/5AAoJEENeEGz1+utPb+MH+wRX9e4LWhaF+FTs5l8xDVOY WUClOZao+Bsg7ZxwAtKWYq2Y/bTUdvB7cwozzA5SNMla08PDttsqETZJioyX4HzN 2YEGmqbmAsMyeLUxKT1myaOZ3s84RIWrGuSicyBLlgbJbvIHsrRaXZ9liBS1Y37M CLVGpqiFNYklW7XNgtxGm49E9E35SZ2ubXBh0N4Av/HD/vlNQMZTIVEcWjeBYFPk XYTSQHco52+mNecBD4WVjEwI6REHUHT9nfyztlItxuPsR/C1LrUDpL/D9kjNvcQt jS2FaD0pmjG/RqY3nK0DM00U1avXvCocsg1aKdFmAwkxjROoVrIHT+YyukdpVnY= =SRmg -----END PGP SIGNATURE----- --=-=-=--