Re: [Bloat] Skype

[Michael Welzl <michawe@ifi.uio.no>]

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 <michawe@ifi.uio.no>
> To: bloat <bloat@lists.bufferbloat.NET>
> 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 <ajb44.geo@yahoo.com>
> To: bloat <bloat@lists.bufferbloat.NET>
> 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 <michawe@ifi.uio.no>
>> To: bloat <bloat@lists.bufferbloat.NET>
>> 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
>>
>
>
> ------------------------------
>
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> End of Bloat Digest, Vol 23, Issue 10
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