Embodiments of the invention provide novel solutions, including systems, methods and / or
software, for providing handoffs between cellular providers and VoIP providers. In some cases, for example, upon the
initiation of a call from a dual-mode cellular phone, the
cellular network (and / or a component thereof) may be configured to store the dialed number and / or substitute a predetermined number for the dialed number. The predetermined number may be associated with a VoIP provider'
s system. Hence, in a particular embodiment, the call may be routed (e.g., via the PSTN) to the VoIP provider'
s system, which may be configured to obtain (perhaps from an
application server) the original dialed number and / or to
route the call (e.g., via the PSTN) to the original dialed number. If the dual-mode phone subsequently obtains IP access, a VoIP connection may be established between the VoIP
system and the phone and / or a handoff may be performed (e.g., in the VoIP
system) to transfer the call from the cellular connection to the VoIP connection. Optionally, the cellular connection may be terminated.