Connection to 3G of AT&T

[EPLAN-User]

Dear Members,
I'm new in this community and I have immediate a question. Hope somebody finds an answer.
I installed the 3CX on my iphone. After 2 h of setting and tweaking with all of the SIP Server Setting and so on I finally get the phone running. works pretty well -only in WLAN-
Now to my question. I get contact only if I'm in the WLAN. If I use the 3G connection of AT&T here in the US I get no connection. 3CX logs in and get connected but if I try to do a call no connection.
Are there any specifc settings necessary or does AT&T not allow to do VOIP. T-Mobile however doesn't let me in at all....
Thanks for answers
Greetings
J.

 

[leejor]

I seem to recall that at&t users were having a problem using VoIP , in the past, over 3G. I'm not sure if that was ever resolved. Hopefully a current at&t user can provide an update.

You might also do a search on the net about any restrictions that at&t put on VoIP services.