[Asterisk-Users] Clicks in audio with TE100P PRI

[Rod Bacon]

Which file does the jitterbuffer setting go in, zaptel or zapata.conf?

I can't find it documented anywhere. What version of zaptel drivers include a 
jitterbuffer?



==========================================
Rod Bacon
Empowered Communications
Ground Floor, 102 York St. South Melbourne
Victoria, Australia. 3205
Phone: +613 99401600    Fax: +613 99401650
FWD: 512237                   ICQ: 5662270
==========================================


Alejandro G wrote:
> 
> I tested all again. No matter if span=1,1,0  or span=1,0,0 if I configure
> jitterbufer=4 I have glitches that I'm almost sure that are "holes" in
> audio.
> 
> If I raise jitterbufer=16 the problem disappear (or becames impercetible).
> Anyway I am interested in understand what is happening.
> 
> 
>>Your issue is very likely the size of the zaptel jitterbuffers setting. If
> 
> the zaptel driver is not
> 
>>immediately available to accept a frame of data it places it in an
> 
> internal queue of pending writes.
> 
>>If that queue is full then the write is refused by the zaptel layer and
> 
> then silently discarded by
> 
>>chan_zap causing a gap in the audio once it is played out of the zaptel
> 
> card. If you crank up the
> 
>>debug level you will probably see 'Write returned -1...' (aka. EAGAIN)
> 
> debugs that mostly correlate to
> 
>>the pops and clicks. Note that the zaptel driver legitimatly (if perhaps
> 
> not appropriately) also
> 
>>refuses data when the channel is muted, such as during DTMF generation and
> 
> at other times, so not
> 
>>_all_ EAGAIN debugs are a sign of problems.
> 
> 
> 
> This makes perfect sense but again some issues of the problem do not match.
> I set debug at level 9 and  there is no message of errors. Another thing I
> do not understand is why the same configuration:
> 
> PAP2 <-> LAN <-> Asterisk <-> TE100P  works perfect, and instead of LAN
> using internet generates the problem. Shouldn't it be the same for both
> configs?
> 
> The only difference I see is that the rtp packets came from another Ethernet
> card, but if I call to terminate calls with another carrier using that eth
> works fine.
> 
> What is clear is that jitterbuffer=16 corrects the problem.
> 
> One more thing: no matter what codec I use, G729 or G711 the sound clicks
> are almost the same.
> 
> Is anyway I could debug at RTP level in asterisk to see what is happening
> and check if there is packet loose?
> 
> Thanks
> 
> Alejandro
> 
> 
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