So… here’s my socat during a call:
# socat - /dev/ttyUSB3,crnl
OK
RING_BACK
CONNECT
AT+BMRAT
+BMRAT: FDD LTE
OK
+DISC: 4,0,0,0,"REDACTED",129
Looks like VoLTE is working for me. This is, again, the BM818-A1 on a T-Mobile MVNO.
So… here’s my socat during a call:
# socat - /dev/ttyUSB3,crnl
OK
RING_BACK
CONNECT
AT+BMRAT
+BMRAT: FDD LTE
OK
+DISC: 4,0,0,0,"REDACTED",129
Looks like VoLTE is working for me. This is, again, the BM818-A1 on a T-Mobile MVNO.