Hope everyone is safe.
I built this FreePBX VM a while ago but now client wants to use it. I use Sangoma as a SIP trunk. When caller dials menus prompt the sound, quality becomes bad (it fluctuates too). The volume goes up and down, and it distorted.
Build: 188.8.131.52 and most modules are updated.
Phones are on same LAN where server is.
I know I must check codecs, but I never done it. If someone could give me right direction what exactly should I check.
Thank you in advance!