Setup VOLTE calling on the HL7648?

This module is specified as supporting VOLTE calling. I cannot find any documentation on what is necessary to set up VOLTE on this module. Can someone point me in the right direction?


This is dependent on the operator i.e. you need to know the APN that the IMS you are connecting to is on. Assuming you are talking about AT&T, given it is certified as voice and data on their network and is an LTE only device I would have expected it to have been shipped with the right config.



I am using an AT&T MVNO which should be compatible. I called them and got the correct settings (not relying on what is on the Internet). Everything looks good but I still get a BUSY when dialing out.

Name: h20mms
APN: prodata
MMS Proxy:
MMS Port: 80
APN Type: *

Original setting:

+CGDCONT: 1,"IPV4V6","reseller","",0,0,0,0,0,0

Setting to above MMSC:


After rebooting result is:

+CGDCONT: 1,"IPV4V6","reseller.mnc410.mcc310.gprs","",0,0,0,0,0,

+CGACT: 1,1

+CGREG: 2,1,"FFFF","0xxxxxD",7,"00

+CEREG: 2,1,"9xx6","05xxxxxD",7

+CIREG: 2,1,1

+CIREP: 1, 1

+HBHV: 0,1
+HBHV: 1,2,0
+HBHV: 2,1
+HBHV: 3,1

+CIREGU: 1,1



Did you forget the semicolon"; "?

Thanks, that was it. Now I have a phone. Before the recent firmware upgrade that semicolon would return ERROR after the command. But now it is necessary. For reference, dialing a ‘+’ after ATD in the US will get an voice error message “We’re sorry, but that number cannot be dialed…”. But in this case it was great to hear anything for the first time.