I have no idea why this is happening, but I'm using FreePBX and i've setup Sangoma talk. It works perfectly fine over WiFi and 4G for some providers (Optus) but when i try to register the phone on 4G on another provider (Telstra), it can't authenticate. It only doesn't work on that network (Telstra).
From my understanding of SIP registration, it should go like:
CLIENT to SERVER: REGISTER
SERVER to CLIENT: 401 Unauthorized
CLIENT to SERVER: REGISTER (containing authentication information)
SERVER to CLIENT: 200 OK
I've setup a wireshark capture on my phone connecting from my Optus SIM and it authenticates without issue. I see in the SIP packet the Authorization, the digest username, the realm, the nonce and URI in the actual packet itself, it looks like the above.
However when i look at the Telstra packet, the authorization part of the packet just isn't there? It's as if it never responds with the Authentication, which is strange, it looks like:
CLIENT to SERVER: REGISTER
SERVER to CLIENT: 401 Unauthorized
CLIENT to SERVER: REGISTER
CLIENT to SERVER: REGISTER
SERVER to CLIENT: 401 Unauthorized
CLIENT to SERVER: REGISTER
CLIENT to SERVER: REGISTER
SERVER to CLIENT: 401 Unauthorized
(and continues)
Does anyone know where i should go for this? Why would my phone behave differently on the 2 networks?
Yes sorry I should have specified. Telstra is on 4g. Works using Telstra broadband, just not 4g. Could it be a NAT issue?