Solved Audio-only participants have no audio

[HExSM]

As I wrote in another thread, our audio-only participants have no audio. This is still not fixed.
With the last update we changed our network configuration and eliminated the second IP on our eth0 network interface, as suggested by @JohnS_3CX. So eth0 has just 1 IP now.

 

[LeonidasG_3CX]

Hi there, can you provide more info on the meeting setup?

• Is the meeting is a scheduled meeting with video disabled by default or are you disabling people's videos manually when they join?
• By no audio, what do you mean exactly?
• Are dial-in affected or browser users or both?

 

[HExSM]

It's a scheduled video conference with the default webconference profile. I then use the dial-in feature. So I call the dial-in number and enter the conference number. I then will be transfered into the webconference.

The dialed in user and the webconference user can't hear each other.

Webconference user which use the browser can hear each other. Only the dial-in user seems to be "deaf-mute".

 

[LeonidasG_3CX]

When the dial-in user connects to the meeting, does he hear nothing or does he hear music on hold?

 

[HExSM]

After the conference number was submitted, he hears the on hold music for 1 second and then there is silence.

 

[LeonidasG_3CX]

In this case, it looks like this must be a firewall issue between your PBX and the MCU you're connected to.

Signaling Connection:
PBX:5001/443 <--> MCU | This is working fine.

Media:
PBX:8500-11000 <--> MCU | Your issue is here.


We've seen firewalls that have built-in geo blocking. Your firewall may be blocking inbound or outbound RTP traffic to and from the MCU. You'll need to check whether geoblocking is on, and you'll need to also add rules for the RTP ports mentioned above.

 

[JohnS_3CX]

Read the section on Network Lockdown specifically:

https://www.3cx.com/user-manual/video-conferencing/troubleshoot/

 

[HExSM]

Thank you. I will try it on the weekend and report back.

 

[HExSM]

The problem was solved. It was indeed the firewall. But the checker gave me a green check mark on every check.

The firewall checker checks the ports 9000:9398 and 10600:10998, which I had opened and dial-in audio didn't work. On https://www.3cx.com/docs/ports/ you write it's 9000-10999, which I opened now and my test worked fine. But @LeonidasG suggests to open 8500-11000. Which ports I really have to open?

Maybe you can update the firewall checker to check the missing ports?

 

[JohnS_3CX]

Hi

9000-10999 is what you have to make sure is open 100% as per our document and this guarantees that the audio will work.

The firewall checker is based on the above document, and it checks the first and last few ports because we assume you have followed the document. We do not check the entire range during this check.

 

[HExSM]

Thanks for the clarification!