CLIR invocation does not work in CSFB

IoT Modules RC76
1

Hi,

I am using a RC7620 device to test voice calls in different conditions.

When I test the CLIR invocation service, I send the AT command “ATDxxxxxxI;” where:

  • “ATD” is the dial command
  • “xxxxxx” is the called number
  • “I” means “CLIR invocation“
  • “;“ means “voice call“

If the device is registered in GSM, when the device originates the call, the CLIR works perfectly (i.e. the calling number is not presented to the called party in the +CRING notification).

If the device is registered in LTE without VoLTE, the device originates the call in CSFB and in such a case the CLIR does not work (i.e. the calling number is presented to the called party in the +CRING notification).

I have also checked the L3 log in both cases:

  • in GSM the SETUP message correctly contains the “CLIR Invocation”
  • in LTE (CSFB), the SETUP message does not contain the “CLIR invocation”

I have encountered this issue with the following firmware releases:

  • RC76xx_Release9_GENERIC_GCF_7620._SWI9X07H_00.08.24.02.exe
  • RC76xx_Release11_GENERIC-VD.exe

Could you please check if this is a known bug for this specific version or if there is a workaround to make CLIR work correctly during CSFB?

Thank you.

2

Does this work under LTE network with VoLTE support?

BTW, how about using AT+CLIR=1

1 Like
3

It works!
Instead of using the ‘I’ or ‘i’ suffix at the end of the ATD command (e.g. ATD<phone_number>I;), I inserted the AT+CLIR command before the ATD command (e.g. AT+CLIR=1;D<phone_number>;).
Thank you very much for the solution.