Consider any call forwarding SCENARIO.... As soon as switch receives Setup, it checks that the Called Party has forwarded OPTION activated and so tries to forward the call. Meanwhile, Switch sends CPG message towards originator saying that Call is in Progress.

A message, sent in either direction during the setup or active phase of the call (ex.inbetween ACM and ANM), indicating that an EVENT, which is of significance, and should be RELAYED to the originating or terminating access, has OCCURRED.

Consider any call forwarding scenario.... As soon as switch receives Setup, it checks that the Called Party has forwarded option activated and so tries to forward the call. Meanwhile, Switch sends CPG message towards originator saying that Call is in Progress.

A message, sent in either direction during the setup or active phase of the call (ex.inbetween ACM and ANM), indicating that an event, which is of significance, and should be relayed to the originating or terminating access, has occurred.