BLF Greyed - STUN over 4G Mobile Broadband router

[Infratech_Michael]

Hi Everyone

We have this very weird problem and hope someone who has faced something similar can provide a solution.

We have 12 Users/Handsets on Yealink T54W across 3 sites.

All configured on STUN and have been working perfectly, over NBN broadband.

One of the sites Which had 2 Handsets has moved to another building and NBN broadband is not available for another month.

To provide the site with temporary internet, we connected them using a Huawei Wireless Broadband Router, which works just fine.

Everything works at this site, from an internet point of view however SIP is not registering over 4G for those 2 handsets, sure enough, we had SIP ALG turned off on this router but still to no avail.

• Tried different SIM cards from 2 Different Providers/Networks and same issue.
• Tried different TP-Link wireless broadband routers and same issue.
• Reset the phones back to the factory settings and reprovisioned as well no luck.

The next step was to try another brand of handsets and it was a Grandstream GRP-2615 for the same extension.

To my surprise, the phone registered and was able to make phone calls in and out, However BLF for Shared Parking and internal extension did not work and all greyed out.

Anyway, hope anyone has faced a similar or same issue and can provide insight.

Thank you in advance.
Michael

 

[JohnS_3CX]

Hi Michae,

STUN cannot work correctly over 4G broadband due to something calle CG-NAT.

Please install an SBC at the site and factory reset and reprovision the phones in SBC mode. This is your best chance to get them working.