Data communications system with session control

A method of operation of a data communications system (5) with session control having a data communications network (10) and at least a first communications device (1), a second communications device (2) and a third commnunications device (3) in communications with the data communications network (10). The data communications network (10) identifies a fault status change in communications with the first communications device (1), generates a session control command (6) with an identification number (7) attached responsive to identifying the fault status change and sending the session control command (6) to at least the second and the third communications devices (2 and 3). At least at the second communications device (2), the second communications device (2) receives the session control command (6), deter-mines from the identification number (7) whether the second communications device (2) is affected by the fault status change and selectively performs a session control action in response thereto.