The present invention allows mobile terminals to initiate calls to either PSTN or non-PSTN addresses through a cellular interface. In operation, the mobile terminal will determine a terminating address to which a call is to be initiated based on user input or selection. The mobile terminal will then determine whether the terminating address should be used to directly initiate a call through the cellular interface. When the terminating address should be used to directly initiate the call, the mobile terminal will directly initiate the call using the terminating address. When the terminating address should not be used to directly initiate the call, the mobile terminal will send the terminating address to a service node. The service node will then initiate an indirect call process using the terminating address to establish the call between an endpoint associated with the terminating address and the cellular interface of the mobile terminal.