[Iaxclient-devel] iaxclient introduces lag

[Florian H. <f.h...@ch...>]

Hi!

Regarding my previous message "Windows choppy / stuttering audio": I 
have unfortunately so far been unable to reproduce the problem on my 
windows development machine. Therefore I'll put this issue aside.
	I have a new problem however. While audio is quite fine compared to 
zoiper and X-Lite on windows on my machine, our iaxclient phone 
produces about 100ms 'lag' compared to zoiper. The lag is the value of 
the 'Lag' field as printed by asterisk when executing 'iax2 show 
channels'. When calling from Zoiper, it always displays 0, compared to 
a fluctuating value when running our softphone (0 at the beginning, 
then increasing up to 130, avg. 100ms). While the 0 from Zoiper may 
actually be due to non-existing support for the RR DELAY value of the 
IAX2 protocol (see [1]), the delay is quite noticable and definitely a 
lot higher than the delay when calling from Zoiper. Just from listening 
I'd say that the actual roundtrip time is about 300-400ms. The two 
machines (asterisk server and windows client) are on the same network, 
plugged to the same switch and there is always <1ms delay when pinging 
the asterisk server from the windows machine. The client I'm calling is 
twinkle on the same linux machine where asterisk runs.
	I have tested all the stable binary releases of iaxclient on 
sourceforge.org in addition to the latest 2.1 beta release. The 
behaviour is always the same.
	Could that be a problem with the settings (echo cancellation, jitter 
buffer, filters), the audio backend, or a bug in the iaxclient code (I 
googled and found some problem reports from 2004 with increasing lag on 
linux machines). See [2].
	Any help and hints would be appreciated!

Cheers,
	Florian

[1] 
http://lists.digium.com/pipermail/asterisk-dev/2005-April/011593.html
[2] 
http://osdir.com/ml/telephony.pbx.asterisk.iaxclient.devel/2005-10/msg00061.html
-- 
DI Florian Hackenberger
fl...@ha...
www.hackenberger.at