What would be the possible reasons of Delivered Event with EC_CALL_FORWARD.
Actually a call has been routed to a station but did not reach to the station. On VDN, alerting event received for the call with EC_CALL_FORWARD reason. Connected number was different one.

Call Forwarding was activated at the destination party (A), the system sent the call to (B). B was the connected party number in the established event.

Thanks John,
Is there any event to find out that call is being forwarded?

Z calls VDN V which directs it to hunt group H and then to agent A and where it forwards to B.

Who are you monitoring?

Have you searched 'forward' in the "TSAPI for Communication Manager Programmer's Reference"? See table 6, Event reports in the Release 4.2 Issue 4 May 2008 version of the document. This assums you are monitoring A. Otherwise it is the cause that informs a monitor of VDN V. I suspect there is an indication in the delivered event for B as well.