A method is provided of establishing network communication later in time between a first endpoint entity accessing an information resource over a network and a second endpoint entity, such as a customer service representative system, associated with that resource. The method uses a service system that can set up a communication session and join endpoint systems to the session to enable them to communicate with each other the network. According to the method, upon the first endpoint entity indicating that it wishes to communicate with a second endpoint entity in the future, the service system generates and stores a session identifier for a communication session to be used in the future and passes a copy of the identifier over the network to the first endpoint entity. Subsequently, the first endpoint entity passes back the session identifier to the service system which, on matching the received identifier with the stored session identifier, joins the first endpoint entity into a communication session with the second endpoint entity. In a preferred embodiment, the session identifier is automatically stored at the first endpoint entity in association with a book-marked rendezvous web page served by the service system, subsequent recall of this page returning the session identifier to the service system.