Patent ID: 8606267

Claim:
A network node comprising: a memory for storing subscriber identity module (SIM) data associated with at least one enterprise user; and one or more processors configured to execute programming code and/or instructions to place an outgoing cellular call by: receiving a request with a first dialing sequence compatible with a Private Branch eXchange (PBX) to initiate the outgoing cellular call, the outgoing cellular call originated by an enterprise user towards a called party when the enterprise user is attached to an external wide area cellular network via a mobile communications device; retrieving a Mobile Subscriber Integrated Services Digital Network (MSISDN) Number in the SIM data, retrieving an International Mobile Subscriber Identity (IMSI) value in the SIM data; generating a derived Country Code value from an International Mobile Subscriber Identity (IMSI) if the MSISDN Number for the enterprise user does not include a Country Code value, constructing an updated mobile number by adding the derived Country Code value to a mobile number from the SIM data associated with the enterprise user, and establishing a second dialing sequence for a call to the enterprise user by sending a circuit-switched call using the updated mobile number.