Experiencing a strange issue that is completely random.
I have FreePBX running on a PC, on premise. I have no audio issues when I call out or when people call in. However, on a regular basis, when I, or any of our users, call out to someone’s cell phone and get their voicemail, the voicemail does not recognize that anyone is speaking. One of two things happens depending on the number we are calling that we are calling (Verizon, T-mobile, Spint, etc.); the call hangs up after 30 seconds or so because it thinks no one is there, or, the voicemail system will cut you off while you are leaving a message telling you that no message has been recoded because we are not speaking. I have also noticed that when this happens, if I hit # or any other key, the voicemail system does not recognize the key press. So either the call is disconnected or we hang-up and then call the number right back and this time it will work with no problems. The voicemail will answer and I am able to leave a message.
I have been able to duplicate this issue on two other systems. Both of those systems are FreePBX running in the cloud on a Vultr. And the exact same scenario occurs.
I can literally call a phone number, get the persons voicemail and leave a message with no problem, or call the same number and experience the issue that I described above. Then, call the number again and it will work with no issue.
I have no clue if this is a FreePBX issue, firewall issue, trunking issue (using Flowroute on all)…
Considering that they are different instances of FreePBX, different hardware and different firewalls, I’m not sure what the problem could be.