Troubleshoot VoIP/SIP Deskphone Issues

UPDATE: SAME ISSUE WITH A SECOND GOHIGHLEVEL-COMPATIBLE DESK PHONE

We have now tried TWO different VoIP/SIP desk phones with GoHighLevel:

1. Grandstream GXP2170
2. Polycom VVX 311

Both phones do the exact same thing:

- They register successfully
- They can make outbound calls through our GoHighLevel phone number
- Outbound caller ID works
- BUT neither desk phone will ring for incoming calls

The only way we can currently receive incoming calls is by forwarding the GoHighLevel number to a cell phone.

At this point, since two completely different SIP phones are doing the exact same thing, this does not appear to be a bad phone issue. It looks much more like a GoHighLevel inbound routing, SIP, NAT, or desk phone configuration issue.

Things we are checking:

- Keep Alive enabled on the SIP phone
- Keep Alive Type set to OPTIONS
- Correct user assigned to the phone number
- Deskphone enabled in the user's Call & Voicemail settings
- Deskphone included in Ring All / Ring Multiple Team Members if applicable
- No IVR, Voice AI, workflow, or forwarding rule intercepting the call
- GoHighLevel's Inbound Test Call under:
Settings → Phone Numbers → Advanced Settings → VoIP Deskphone (SIP) → Test Calls

The important part is this:

TWO DIFFERENT PHONES CAN CALL OUT BUT NEITHER WILL RING INBOUND.

We are looking for someone who has actually set up physical SIP desk phones with GoHighLevel and has both incoming and outgoing calls working correctly.

If you specialize in VoIP/SIP and GoHighLevel and know how to troubleshoot this, please reach out.

We are happy to pay someone who actually knows how to fix it.