Many types of contact center are arranged such that communications between contact center agents and customers or other end users are contingent upon, or dependent upon, successful operation of the contact center itself. However, if the contact center is not working for any reason, contacts cannot be directed between agents and end users. This is addressed by directing contacts between an end user and contact center agents, without the need for operation of the contact center itself. In order to achieve this a plurality of associations between contact center agent addresses and the contact center address are made, stored and prioritised at a communications network node.