From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-out2.uio.no (mail-out2.uio.no [IPv6:2001:700:100:10::58]) (using TLSv1 with cipher DHE-RSA-AES256-SHA (256/256 bits)) (Client did not present a certificate) by huchra.bufferbloat.net (Postfix) with ESMTPS id 242CE21F169 for ; Mon, 19 Nov 2012 05:25:08 -0800 (PST) Received: from mail-mx5.uio.no ([129.240.10.46]) by mail-out2.uio.no with esmtp (Exim 4.75) (envelope-from ) id 1TaRLV-0004Gr-AH for bloat@lists.bufferbloat.net; Mon, 19 Nov 2012 14:25:05 +0100 Received: from 205.158.58.41.ptr.us.xo.net ([205.158.58.41] helo=[10.0.0.127]) by mail-mx5.uio.no with esmtpsa (TLSv1:AES128-SHA:128) user michawe (Exim 4.80) (envelope-from ) id 1TaRLT-0004ny-U9 for bloat@lists.bufferbloat.net; Mon, 19 Nov 2012 14:25:05 +0100 Message-Id: <1AF294D3-4279-4707-B699-EE4C512264B0@ifi.uio.no> From: Michael Welzl To: bloat In-Reply-To: <81564C0D7D4D2A4B9A86C8C7404A13DA04B32E@ESESSMB205.ericsson.se> Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v936) Date: Mon, 19 Nov 2012 14:25:00 +0100 References: <81564C0D7D4D2A4B9A86C8C7404A13DA04B32E@ESESSMB205.ericsson.se> X-Mailer: Apple Mail (2.936) X-UiO-SPF-Received: X-UiO-Ratelimit-Test: rcpts/h 1 msgs/h 1 sum rcpts/h 3 sum msgs/h 1 total rcpts 220 max rcpts/h 15 ratelimit 0 X-UiO-Spam-info: not spam, SpamAssassin (score=-5.0, required=5.0, autolearn=disabled, TVD_RCVD_IP=0.001, UIO_MAIL_IS_INTERNAL=-5, uiobl=NO, uiouri=NO) X-UiO-Scanned: C5C345A4C3F74247C778A114C9B07B782F75EA9D X-UiO-SPAM-Test: remote_host: 205.158.58.41 spam_score: -49 maxlevel 80 minaction 2 bait 0 blacklist 0 greylist 0 ratelimit 0 Subject: Re: [Bloat] Skype 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: Mon, 19 Nov 2012 13:25:08 -0000 Ohh... rats, I didn't check that. Quite possible. Cheers, Michael On Nov 19, 2012, at 11:27 AM, Ingemar Johansson S wrote: > Hi > > Been a year or so since I read about the inner secrets of Skype so > this may be old.. > I would suspect that your Skype session runs over TCP (via a Relay). > This may happen e.g when a firewall blocks UDP. > TCP (possibly in combination with a lossy WiFi connection) is what > creates the high latencies. > > /Ingemar > ------------------------------ > > Message: 2 > Date: Sun, 18 Nov 2012 15:57:53 +0100 > From: Michael Welzl > To: bloat > Subject: [Bloat] Skype > Message-ID: <647D57F5-24CE-4006-AD2A-74141C84C3CB@ifi.uio.no> > Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes > > Hi, > > I have repeatedly noticed that Skype sometimes, in a long > conversation involving video, can create massive audio delays (in > the order of multiple seconds). This has happened to me in a > conversation from a hotel room in the US to my home in Oslo (where, > apologies, I haven't yet looked into de-bloating my modem and access > point), and from my office in Oslo to someone else's office in the US. > > I'm wondering: was that always due to bloated equipment along the > path (including the end hosts), or does Skype poorly handle its > internal buffers? > > Any experiences? I suppose the way to find out is to run Skype over > a verifiably de-bloated path. If, then, the problem never occurs, > the fault is with the equipment and not with Skype (and vice versa). > > Cheers, > Michael > > > > ------------------------------ > > Message: 3 > Date: Sun, 18 Nov 2012 08:09:03 -0800 (PST) > From: Alex Burr > To: bloat > Subject: Re: [Bloat] Skype > Message-ID: > <1353254943.93761.YahooMailNeo@web126202.mail.ne1.yahoo.com> > Content-Type: text/plain; charset=us-ascii > > I have noticed delays - although I don't think multiple seconds - > but I think that it may be skype trying to make the best of a bad > connection. I don't have any knowledge of the internals of the skype > client, but I suspect that they take the view that delayed audio is > better than incomprehensible audio - I think I have even heard it > actually repeating the last bit of audio before a glitch, to give > you a better chance to understand the next bit, and presumably > catching up when the opportunity arises. > > So, an experiment to rule out skype might need to use not just a de- > bloated path, but one with known packet loss. > > > Alex > > > > ----- Original Message ----- >> From: Michael Welzl >> To: bloat >> Cc: >> Sent: Sunday, November 18, 2012 2:57 PM >> Subject: [Bloat] Skype >> >> Hi, >> >> I have repeatedly noticed that Skype sometimes, in a long >> conversation >> involving video, can create massive audio delays (in the order of >> multiple seconds). This has happened to me in a conversation from a >> hotel room in the US to my home in Oslo (where, apologies, I haven't >> yet looked into de-bloating my modem and access point), and from my >> office in Oslo to someone else's office in the US. >> >> I'm wondering: was that always due to bloated equipment along the >> path >> (including the end hosts), or does Skype poorly handle its internal >> buffers? >> >> Any experiences? I suppose the way to find out is to run Skype over a >> verifiably de-bloated path. If, then, the problem never occurs, the >> fault is with the equipment and not with Skype (and vice versa). >> >> Cheers, >> Michael >> >> _______________________________________________ >> Bloat mailing list >> Bloat@lists.bufferbloat.net >> https://lists.bufferbloat.net/listinfo/bloat >> > > > ------------------------------ > > _______________________________________________ > Bloat mailing list > Bloat@lists.bufferbloat.net > https://lists.bufferbloat.net/listinfo/bloat > > > End of Bloat Digest, Vol 23, Issue 10 > *************************************