A system for the handling of calls by a packet-based telephony system by which calls invoking features not implemented on the packet-based system are handed off to an existing legacy circuit-switched telephony system for further processing. Initial address messages are forwarded to a packet network feature server, which determines whether the features invoked by the call can be provided. If not, the feature server assigns the call a trunk selection parameter according to the type of feature invoked. The trunk selection parameter is conveyed to a connection gateway, which routes the call on one of a plurality of voice trunks. The call is received by a circuit-switched switching system for further processing according to the feature invoked.