Realm translation in an ims network

At least one non-transitory computer-readable medium, carrying instructions, which when executed by at least one data processor, performs a method for use in a telecommunications network for routing communications, the method comprising:

• receiving a request from an initiating device to establish a service connection session between the initiating device and an endpoint through an Internet Protocol Multimedia Subsystem (IMS) session,
• wherein the initiating device is assigned to a first realm, and
• wherein the endpoint is associated with a second, different realm;
• providing a registration message based on the request to create the IMS session,
• wherein the registration message identifies the initiating device as being assigned to the second realm;
• wherein the IMS session is created between the initiating device and the endpoint,
• wherein, during the session, the first realm is translated into the second realm upon receiving messages from the initiating device;
• and
• wherein, during the session, the second realm is translated into the first realm upon receiving messages from the endpoint.