Method of communicating between a user and a network

摘要

A method of communicating between a user and a network, the method comprising registering with a first central control unit in a first area; registering with a second central control unit in a second area; wherein the second registration is valid concurrently with the first registration; defining a set of priorities by which each control unit determines route selection for a call; and routing a call via the first or second control unit accordingly.