Hi,
I have a Quectel **EC25-AUX** module (Firmware: **EC25AUXGAR08A03M1G**) installed in a cellular intercom / door phone system in New Zealand.
After the 3G shutdown, the module successfully registers on **LTE Band 28** (Spark network) with good signal, but when anyone calls the SIM number it immediately returns **“User Busy”** on the caller’s phone.
The module responds to AT commands and I have already tried:
- AT+CLIP=1, AT+CRC=1, AT+QTONEDET=1, AT+CSNS=1, AT+CBST=0,0,1, etc.
- Forcing LTE only with AT+QCFG=“nwscanmode”,3,1
DTMF detection works, but the device never answers incoming voice calls.
Could you please provide the **latest firmware** for EC25-AUX (or a newer GAR version) that has better voice call handling for intercom applications?
Thank you!
Les