The present disclosure includes a system and method for managing handovers between network devices. In some implementations, a method includes receiving a request to handover a call session from a femtocell to a macrocell associated with a cellular core network. The femtocell comprise cellular radio technology. A Session Initiation Protocol (SIP) message is generated based, at least in part, on the handover request. The SIP message is transmitted to a communication node associated with the cellular core network.