Hello, I have a terrible problem. I have installed the version 1.6. When I make a call if I talk the voice of the other person is blocked, We cannot keep a call full duplex or talk one or the other but the two at the same time it’s impossible because I can not hear to the other person while I talk.
do you have enough network bandwidth?
When you receive the call the full duplex call work?
The call is SIP, IAX2, DAHDI?
Dahdi call, I have enough bandwidth because when the call is SIP i have no problem.
I have the same problem too.
My system: Asterisk 1.4.23.1 + dahdi 2.1.0.4 + TE122 + VPMADT032
When I call an outside number over the PRI line, I can hear the other side clearly if I don’t speak, but once I speak at the same time as the other side, I can’t hear the other party clearly, the sound breaks like half-duplex.
Googled arround, tried to reduce rxgain and txgain, it does make a little bit of improvement, but there is breaks still when I increase my volume. Which means I am not allow to shout at anyone over the phone, must be very gentle…
Is the Echo Cancellation card causing the problem? I checked my firmware of VPM is up to date version 107.
I tested this problem by calling into another company’s IVR, then I make a long “woooooo”, the IVR audio become broken. Then I tried call into my own IVR, no matter how loud I shout it is fine. This indicates that my digium card is giving the problem, but not sure if it is the card or the echo module.
seems no one cares about this.
I found more things about this problem, which involves changing wcte12xp module parameters, will try it out on saturday and post the outcome of it.
I’m going to try the following:
A) Increase vpmnlpthresh, default value is 24.
B) Change vpmnlptype to suppression and vpmnlpmaxsupp=11
We have the problem in two asterisk which have the same configuration as your. We change the card TE121 to TE220 y the problem has disappeared .
So the problem is with card TE121 and echo cancel VPMADT032 . I supposed that the problem is with the echo cancel because if we don’t put the echo cancel the problem with the half duplex is removed.
I also have a “full duplex” problem that occurs after a while during a call. When one of the sides is talking the other side must be quiet. If a sound is made the other side is no longer heard.
This is with a Digium TDM403E, so also with the VPMADT032-module.
I have not edited options concerning the EC-module. The only thing I have done is changed the rxgain and txgain, because the feedback I got was that the conversation was rather quiet…
Should look into it to see if the gain is causing this “one-way-traffic”.
[quote=“caleb19”]seems no one cares about this.
I found more things about this problem, which involves changing wcte12xp module parameters, will try it out on saturday and post the outcome of it.
I’m going to try the following:
A) Increase vpmnlpthresh, default value is 24.
B) Change vpmnlptype to suppression and vpmnlpmaxsupp=11[/quote]
the vpmnlpthresh and vpmnlpmaxsupp options are not available in wcte12xp. So I just turned off the echo cancel module, and my problem is gone, it works fine now.
Then I tried 4 different machines, all these servers have te122p + vpmadt032, they all have the same problem. 
The cure now is to disable EC module, by using
"options wcte12xp vpmsupport=0" in /etc/modprob.d/dahdi and add “echocanceller=mg2” in /etc/dahdi/system.conf
rxgain and txgain don’t really work, unless you turn it very soft 
This is really bad, we paid for the EC card and get more trouble. Hope digium will come out a solution for this, quickly. I wont purchase any more vpmadt032 for future deployments, use mg2 is good enough, digital lines are not as bad as analog.
Btw, the two ports and 4ports E1/T1 cards are ok with vpmadt064 and vpmadt128, only the 1port card with vpmadt032 is giving ths problem.