A switch for use in a telecommunication network is provided that includes a plurality of call control agent functions and a call control function. At least two of the call control agent functions are associated with different signaling protocols. The signaling protocols define a plurality of signaling control primitives. The call control function is operable to control routing of telephone calls through the switch. The call control function is accessed using an application programming interface (API). The API includes a plurality of classes defining objects representing the signaling control primitives.