AT command CHLD=3 on SIMCOM508 modem to make multiparty call returns ERROR.

[kishoreinme]

Hello

I have a SIMCOM508 modem connected to minicom on ubuntu.
Iam able to make calls, add, hold, wait, swap and sms except multiparty conference call.

I have followed the steps in http://www.microchip.ua/simcom/GSM-G...0Note_V1.0.pdf
to try this

The final AT+CHLD=3 returns just an ERROR from the modem.

is there any sequence to be followed doing this?
could someone help out?
Thanks

[kubeek]

Are you should it works in a standard phone with your simcard? The feature could be disabled at the provider.

[kishoreinme]

Dear Kubeek

Thanks for the pointer. checked it. the operator support was disabled. the problem solved.