Abstract: Disclosed herein are methods and systems that may help to dynamically rout calls in a communication network where circuit-switched fallback (CSFB) is implemented. In particular, a user equipment (UE) may include an identifier of an interworking server (IWS), which relayed a page message from a first access network to a second access network for transmission to the UE, in the corresponding page response message that the UE sends to the first access network. The inclusion of the IWD identifier in the page response message may allow the switch that receives the page response message to detect when the corresponding voice call was received at a different switch in the first network, and responsively initiate an inter-system handoff when this is the case.