No audio on Softphone with VPN (Short numbers)

[HelloALU]

Hello,

I am an IT technician, I work in a City Hall in France (sorry for my bad English, it's quite embarrassing on such a technical forum) and we're deploying the IP Desktop Softphone for our internal use while remote-working.

However, we're facing a strange issue since a few months (in fact it never worked correctly). We use the Softphone over Pulse Secure VPN, on Windows 10 laptops with the V11 of the Softphone.

The issue is : When we call some short numbers, or when we receive calls of short numbers of our enterprise (when we are inside our enterprise we just have to dial the last 4 digits of the full phone number to call people), the connection is made, but the audio is blank, both way. We can't hear people and they can't hear us.

So we have to hang up, and to dial the full phone number on 10 digits including the exit 0, to establish a call. It's rather annoying because we are a Hotline service and we prefer answering directly the calls as they arrive.

We're investigating the issue but we are not finding anything useful right now. It seems (but only seems) that not all the numbers are impacted, also.

Do you have a checklist for this kind of issue ?

Thanks

[vad]

Looks like you have problem:
- or with RTP traffic between Softphone and called user (when you dial full number I think you have another voice flow - to VoIP board or something else)
- or with codacs (G729, G711)...

[frank]

Check out your firewall settings.
Signaling is one path, voice flow is another path.
If you run TCPDUMP / Wireshark on your end points you should see something missing.