Ring extension group without answering Trunk?

Is it possible to have Asterisk react to the ring on a trunk and ring an extension group without actually answering the trunk?

I need this to happen as I have set up call diversion on my BT trunk so that unanswered calls go to a virtual reception service rather than VM.

I have a dedicated box with Asterisk (actually Elastix) installed and a 4 line TDM400P card. Two lines are connected to internal DECT phones and two are for external trunks: one personal and one business. Currently, a call on the business trunk causes one of the DECT phones and a couple of SIP extensions to ring in parallel. If there is no answer, calls go to VM. I want unanswered calls to go to the external answering service and have enabled delayed call diversion on the BT trunk. However, Asterisk always answers the call before ringing the extensions, so the call never diverts.

Gareth

What you ask is the normal behaviour. You have to do something that forces an Answer, for it to behave otherwise.