UMA T-Mobile Calling

[gatorback]

I am running Merlin's 378.55 on a RT-AC68U that was formerly a T-Mobile Cellspot.

For some reason UMA (wifi) calling is not working and the ANDROID handset indicates: Error: REG99 "unable to connect"

When I took the handset to the store to reproduce the problem I did not experience this problem. That seems to indicate that there may be a problem somewhere between the router and modem. To top it off, I have the same router / firmware in my other home and had no problems with wifi calling. So that suggest the opposite.

Has anyone seen this problem or know how to test (simulate) wifi calling? Thanks.

Update: wifi calling works from Blackberry handset, so I think that I can surmise that the network is not impeding the call.

 

[sfx2000]

Could very well be a problem on T-Mobile's end - the feature, if I recall correctly, is implemented differently on Android vs. Blackberry vs. iPhone.

One thing to try is to restart the phone, and if you're still getting the error, I would call their helpdesk - don't mention that the Cellspot has been reflashed..

 

[gatorback]

Update: two other TMO handsets reported DNS errors so this morning I decided to update the DNS settings:

Advance Settings => LAN => DHCP Server => DNS Server 1 = 8.8.8.8 (Google DNS)

This literally resolved the problem.

It was challenging in that 3 of 4 handsets (Galaxy S5, S3, BBQ10) suffered from this DNS limitation, returned different 2 different error messages, whereas the older BB9700 worked without the above DNS change. Perhaps the IP address was cached only in the BB9700. All handsets worked correctly in the other home with the identical router / firmware, without the above Google DNS entry.

It would be nice to know the FQDN that was resolved because in the future, if there is an error, one could test to see if the FQDN is resolved to a proper IP address.