[Asterisk-Users] Help with IAX , voice Distortion or Breakage.

[Alexey Ostrovsky]

Alexey Ostrovsky wrote:

> Hello all,
>
> We have the following problem:
>
> When calling via iax, the sound is off after a while - most often 
> after about 5 minutes (sometimes later or earlier) - at one end or at 
> both ends. While the channel is up, and packages are still being 
> transmitted, you just can't hear anything. Sometimes you can hear 
> something just a little, but with the voice greatly distorted, 
> sounding like a robot's voice.
> This problem emerges whichever phone is called or whichever phone a 
> call is made from (softphone, ipphone, local phones thru TDM cards)
>
> System details:
>
> - Linux Slackware 9.1 kernel 2.4.6
> - CPU PIII 800
> - RAM  500 Mb
> - motherboard Asus TUSL-2c
> - hard drive IDE
>
> - Asterisk last cvs update
> - 3 TDM400 cards - codec g729 voiceage
>
> Help please.
> May be somebody have same problem.
>
> Thank you.
>
Some more information about that  problem.

Our system was tested with various codecs and protocols.
The results are as follows:

All calls one after another between two asterisk system (one in UA 
another in US).

IAX2/ulaw    -    5 calls    20-25  min  duration    ----    All OK
IAX2/gsm     -     after 10 min -  one-way  audio   -   channels up
                            30 min   -   OK
                            5 min  -   one-way  audio  -   channels up
                            20 min  -   one-way  audio  -  channels up
                            55 min   -  one-way  audio  -  channels up
                            30 min   -   OK

IAX2/g729           3 min  -   one-way  audio  -   channels up
                            15 min  -   one-way  audio  -  channels up
                            65 min   -  one-way  audio  -  channels up
                            30 min   -   OK
                            50 min  -   OK

IAX/ilbc               30 min  -   OK
                            35 min   -   OK
                            10 min   -   noise
                            30 min   -   OK
                            30 min  -  OK

SIP/gsm                30 min  -   OK
                            30  min  -   OK
                            10 min   -  one-way  audio  -  channels up
                            30 min   -  OK
                            7 min  -   one-way  audio  -  channels up

SIP/g729              30 min  -   one-way  audio  -  channels up
                            25  min  -   OK
                            10 min   -  one-way  audio  -  channels up
                            30 min   -  OK
                            12 min  -   one-way  audio  -  channels up

So,  as you see in my case ulaw  is better than others.   
But  it  is too much for my  net link. I have 256 kbit   DSL  now.
 
   
For now I am using  ilbc fore iax2.   
It  doesn't have a  "one-way  audio"   problem (for now) on our system.   
   
May be this will help to understand  what is wrong.  
 
Thanking you in advance,                             

-- 
Best regards,
	Alexey Ostrovsky