System and method for terminating communication sessions with roaming mobile devices

A method for establishing a communication session with a mobile device having a registered internet protocol multimedia subsystem (IMS) session in a visiting cellular network, the method comprising:

• receiving addresses of application services utilized by mobile devices having registered internet protocol multimedia subsystem (IMS) sessions in visiting cellular networks;
• storing each received address of an application service that is associated with a mobile device in conjunction with an identifier of the associated mobile device;
• receiving a Send Routing Information (SRI) message from a mobile switching center, the SRI message reflecting a request to establish a communication session between a requesting mobile device and a terminating mobile device;
• routing the SRI message to an application service associated with the terminating mobile device by:
• retrieving the address of an application service associated with the terminating mobile device from the stored addresses;
• and
• forwarding the SRI message to the retrieved address;
• in response to the forwarded SRI message, receiving an IMS roaming number associated with the terminating mobile device:
• and
• providing the IMS roaming number to the mobile switching center in order to facilitate establishing the communication session between the requesting mobile device and terminating mobile device.

A non-transitory computer-readable storage medium containing instructions for establishing a communication session with a mobile device having a registered internet protocol multimedia subsystem (IMS) session in a visiting cellular network, the method comprising:

• receiving addresses of application services utilized by mobile devices having registered internet protocol multimedia subsystem (IMS) sessions in visiting cellular networks;
• storing each received address of an application service that is associated with a mobile device in conjunction with an identifier of the associated mobile device;
• receiving a Send Routing Information (SRI) message from a mobile switching center, the SRI message reflecting a request to establish a communication session between a requesting mobile device and a terminating mobile device;
• routing the SRI message to an application service associated with the terminating mobile device by:
• retrieving the address of an application service associated with the terminating mobile device from the stored addresses;
• and
• forwarding the SRI message to the retrieved address;
• in response to the forwarded SRI message, receiving an IMS roaming number associated with the terminating mobile device;
• and
• providing the IMS roaming number to the mobile switching center in order to facilitate establishing the communication session between the requesting mobile device and terminating mobile device.