Patent ID: 8885601

Claim:
A system comprising: a first user device configured to communicate with a second user device, the first and second user devices being installed with a respective instance of a communication client application for conducting voice or video calls over a packet-based network; wherein each of the instances of the communication client application is associated with a same user identifier, a first of said instances of the communication client application is associated with a first sub-identifier, and a second of said instances is associated with a second sub-identifier; and the instance of the communication client application on the first device is configured to: during an ongoing call between the first user device and a remote user device conducted over a first network connection established based on said user identifier and the first sub-identifier, establish a second network connection over the packet-based network by sharing said user identifier and the second sub-identifier with the remote user device; and switch the call to the second network connection based on information mapping the first user device and the second user device to sub identifiers contained in a look-up table accessible to the first user device and the second user device such that the call, after being switched, continues via the second user device.