Call cuts off when using softphone

When I use softphone (Grandstream wave, Zoiper, etc…) and the two people talk at the same time, the call cuts off.
In the FXS gateway this problem does not happen.

You’d need to provide an actual SIP trace (either sip set debug on, or pjsip set logger on, depending on which SIP channel driver is in use) to show who is terminating the call.

Hi Jcolp, the call does not end, the audio is missing while both people are talking at the same time. If each person waits for the other to speak, the problem does not occur.

Okay, so you’re referring to the audio itself being cut off. “Cut off” can mean a lot of things.

This would be the softphone or mobile phone itself - so you’d likely need to seek help from either Grandstream or Zoiper to see if there’s settings. Asterisk itself just passes through whatever audio it gets.

Agree that this isn’t Asterisk.

Soft phones are likely to be used handsfree, which means there is some sort of VOX (voice operated switch), to prevent echoes. Good VOX systems also have anti-VOX, so that, once there is incoming audio, the VIOX is temporarily disabled. With the long round trip times of VoIP it is much more likely that both people will will start talking close enough together that both phones switch on the microphone and switch off the speaker.

If this is happening, a packet capture, or enabling monitor/mixmonitor, on Asterisk, will show that audio is going across the network in both directions.

If I understand the bit about the FXS gateway, that is probably assuming conventional handsets, where there is little acoustic echo, and that acoustic echo is simple (a single delay time), meaning that echo cancellations techniques are sufficient.

Hi david551, the cause may be this, when the softphone detects sound in the microphone it disables the audio in the speaker, I am researching the subject, thanks.

That’s what VOX implies (it also means that when no sound is detected, the microphone is isolated from the line).

David 551, Grandstream support said that the softphone does not have this functionality (VOX), is it Android that causes this?

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