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?
Is it a 4G only issue? Does the Telstra phone work over WiFi?
Yes sorry I should have specified. Telstra is on 4g. Works using Telstra broadband, just not 4g. Could it be a NAT issue?
My thought is NAT issue, though I’d have thought Sangoma Talk would use a STUN server to handle that.
The fact the phone keeps sending the REGISTER over and over, suggests it’s not receiving the 401 response. I’d start by double checking the Telstra 4G IP address,
then making sure the REGISTER has the correct IP in the Contact header.
I’m not sure what logging you’ve setup on the phone, but are you able to see the 401 arrive on the phone?