According to an embodiment, a mobile device includes wireless access circuitry configured to access a wireless communication network; a processor for executing a communication client application to conduct a packet-based call with a remote device via a channel established over the wireless communication network, the communication client application configured to monitor at least one network parameter; a hardware processing module selectively operable to implement a processing function; a software processing module selectively executable to implement said processing function; and a selection mechanism for supplying the call to one of the hardware processing module and software processing module based on the at least one monitored network parameter.