Failed to create media streams (code: 29)
This error message, usually indicates that Zoiper cannot negotiate/ create the media streams for some reason. This error is generic, thus there is no certain option that you can change to resolve it.
However, there are few things which you can try:
1. The most common issue is that something I using the default ports for the audio (RTP) stream. Zoiper has a detection mechanisms to prevent such collisions from happening, however in some cases if you have traffic control applications, dynamic firewall or something else, Zoiper might not be able to lock the port or the check may not return proper result.
In this case, the symptom will be: Every first(or first few calls) will fail with the error "Failed to create media streams (code: 29)", until eventually Zoiper finds an unlocked port. ( By default Zoiper tries to use port: 8000, for the RTP. )
This might also happen if you are in a very busy environment where lots of machines are trying to use the same listening ports behind badly configured NAT.
Under Zoiper -> Settings -> Advanced, you can find an option called "Open random port above 32000" for RTP. Just enable it.
2. Audio device access failure. In this case, Zoiper is unable to access the audio device on your system for some reason.
Verify if your drivers are installed properly and that you don't have any software which might request exclusivity over the audio device.
3. Failed codec negotiation. You should always consult with your service provider which codecs are supported and used by them. You should also follow their advice on the exact codec priority.
Make sure that in Zoiper5 only the codecs supported by your service provider are enabled. You can find information how to set the codecs in Zoiper5 on our manual.