Zyxel 3302 - 4G Router - Issues with multiple phones

[COM-TEL]

Hello,

I have a customer who has moved to 4G and is using a Zyxel 3302 router with two Yealink phones.

Phone 1 - Yealink T19 - single extension - auto provisioned - No Issues.
Phone 2 - Yealink T22 - end of life phone with two extensions, manually configured.

All firmware has been updated to the latest available.

The issue is with Phone 2. It will not register on the 3CX system since moving over to 4G. Prior to this on ADSL and Fibre, it worked fine.

Has anyone else had experience of this 4G router or with 4G in general?

The customer has an additional Yealink T22 in a different office but using ADSL and THAT connects to the 3CX system without any problems.

I know the registration details on Phone 2 are correct so am thinking that this may be an issue with the router.

Does anyone else have any thoughts?

Thank you.

EDIT: In addition to this, assuming it is a router issue, would an SBC resolve this?

 

[leejor]

It may very well depend on the configuration of the 4G set up. Is the router assigned it's own public IP as it probably had been with ADSL? Is it using IPV6, that might cause an issue. I assume that both sets are each using a unique local port. What does the registration, for each set look like in the Activity Log? One would seem to be correct, how does the other differ? Has there been any port forwarding done in the 4G router?
Once you use more than one SIP device (STUN) behind a router, depending ion the router, you can run into problem, usually "no audio" issues.

My first step would be to see what the registrations look like, that will probably give you a clue as to what may need changing on the router.

 

[COM-TEL]

My first step would be to see what the registrations look like, that will probably give you a clue as to what may need changing on the router.

Thanks leejor. Half the problem is that Phone 2 wont register on the system and not appearing in any of the Event logs on 3CX. This tells me its not getting past the router in the first place.

Phone 1 is auto provisioned and therefore I think the Stun setting is enabled by default.

I need to get into the Router and give it a thorough thrashing!