Using the IMSI value from the SIM card data to make an external call

1. 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.

2. The network node of claim 1 , where

retrieving an International Mobile Subscriber Identity (IMSI) value in the SIM data includes removing a plus sign from a mobile number of the mobile communications device.

3. The network node of claim 1 , where the one or more processors are configured to construct the updated mobile number by:

extracting a Mobile Country Code (MCC) value from the IMSI value, and

adding the MCC value to the mobile number.

4. A method for facilitating integration of an outgoing cellular call as an enterprise call, comprising

receiving a request for an outgoing cellular call from an enterprise user towards a called party where the enterprise user is attached to an external wide area cellular network via a mobile communications device;

retrieving a mobile number and an International Mobile Subscriber Identity (IMSI) value from subscriber identity module (SIM) data associated with the enterprise user;

generating a derived Country Code value from the IMSI value if the mobile number for the enterprise user does not include a Country Code value;

adding the derived Country Code value to the mobile number to generate at least part of a first dialing sequence to the mobile communications device;

generating a second dialing sequence to the called party; and

sending the first dialing sequence and the second dialing sequence to a call switching node for establishing a first call leg to the mobile communications device using the first dialing sequence and a second call leg to the called party using the second dialing sequence such that the second call leg contains an enterprise address of the enterprise user as a calling line identity.

5. The method of claim 4 , further comprising adding an International Direct Dialing code to the first dialing sequence if the derived country code does not match a dialing zone for a call switching node which will establish a first call leg to the mobile communications device using the first dialing sequence.

6. The method of claim 4 , further comprising adding a National Direct Dialing code to the first dialing sequence if the derived country code matches a dialing zone for a call switching node which will establish a first call leg to the mobile communications device using the first dialing sequence.

7. The method of claim 4 , further comprising sending the first dialing sequence to a Private Branch eXchange (PBX) which will establish a first call leg to the mobile communications device using the first dialing sequence.

8. The method of claim 4 , where retrieving the mobile number comprises retrieving a Mobile Subscriber Integrated Services Digital Network (MSISDN) Number comprising a Country Code field from SIM data associated with the enterprise user.

9. The method of claim 4 , where generating the derived Country Code value comprises extracting a Mobile Country Code (MCC) value from the IMSI value.

10. The method of claim 9 , where generating the derived Country Code value comprises using the MCC value to access a table of Country Code values to retrieve the derived Country Code value.

11. The method of claim 4 ,

wherein the retrieving an International Mobile Subscriber Identity (IMSI) value in the SIM data includes removing a plus sign from a mobile number of the mobile communications device.

12. A method for making an enterprise call from a mobile device attached to an external wide area cellular network, comprising:

receiving a request from an enterprise user to initiate an external call from the mobile device to a called party; and

constructing an updated mobile number when a mobile number from subscriber identity module (SIM) data associated with the enterprise user does not include a Country Code value by generating a derived Country Code value and adding the derived Country Code value to the mobile number;

establishing a first call leg to the enterprise user by sending a circuit-switched call using the updated mobile number;

establishing a second call leg to the called party upon receiving an indication that the first call leg has been established; and

patching the first call leg and the second call to establish an end-to-end communications path between the enterprise user and the called party.

13. The method of claim 12 , where constructing the updated mobile number comprises:

retrieving a mobile number from SIM data associated with the enterprise user;

determining whether the mobile number from the SIM card data includes a Country Code value;

retrieving an International Mobile Subscriber Identity (IMSI) value from the SIM data associated with the enterprise user if the mobile number from the SIM card data does not a Country Code value; and

constructing the updated mobile number by generating a derived Country Code value from the IMSI value and adding the derived Country Code value to the mobile number.

14. The method of claim 13 , where retrieving the mobile number comprises retrieving a Mobile Subscriber Integrated Services Digital Network (MSISDN) Number from the SIM data associated with the enterprise user.

15. The method of claim 14 , where determining whether the mobile number from the SIM card data includes the Country Code value comprises determining whether the MSISDN Number includes a Country Code.

16. The method of claim 13 , where constructing the updated mobile number comprises extracting a Mobile Country Code (MCC) value from the IMSI value and adding the MCC value to the mobile number.

17. The method of claim 13 , further comprising:

wherein the retrieving an International Mobile Subscriber Identity (IMSI) value in the SIM data includes removing a plus sign from a mobile number of the mobile device.

18. The method of claim 12 , where constructing the updated mobile number comprises removing a “+” sign from the mobile number.

19. The method of claim 12 , where constructing the updated mobile number comprises adding an International Direct Dialing code to the updated mobile number if the derived Country Code value does not match a country location indicator for a call switching node which will call the mobile device.

20. The method of claim 12 , where constructing the updated mobile number comprises adding a National Direct Dialing code to the updated mobile number if the derived Country Code value matches a country location indicator for a call switching node which will call the mobile device.