Patent ID: 8798075

Claim:
A method in a first communication device for setting up a peer-to-peer IP connection between the first communication device and a second communication device, where the first communication device is associated with a first Subscriber Identity Module (SIM) and the second communication device is associated with a second SIM, the method comprising: sending, to the second communication device, using a messaging service that is available to the first communication device based on the first communication device being associated with the first SIM, a request for setting up the peer-to-peer IP connection between the first communication device and the second communication device, the request being directed to a particular port of the second communication device, the particular port being associated with an application, the request causing the application to automatically start in the second communication device based on the second communication device receiving the request via the particular port; receiving, by the first communication device and from the second communication device, an identifier identifying the first communication device and an IP address of the second communication device, the identifier and the IP address of the second communication device being included in a message received from the second communication device, the message being sent by the second communication device based on the request being directed to the particular port; processing, by the first communication device, the identifier to form a signature associated with the first communication device, the signature being different from the identifier; sending, by the first communication device, the signature to the IP address of the second communication device to set up the peer-to-peer IP connection between the first communication device and the second communication device, the second communication device authenticating the first communication device based on the signature, and the peer-to-peer IP connection between the first communication device and the second communication device being set up based on the second communication device authenticating the first communication device based on the signature.