What is the need of CPG message in ISUP protocol? - Telecommunications

What is the need of CPG message in ISUP protocol?

- CPG message is sent by the switch towards originator.

- When the switch receives the setup, the call is forwarded.

- When the message is sent it is signaled that the call is progress.

- During the setup or active phase of a call, a message is sent.

- This signifies the relayed to the originating has occurred.