A method and apparatus for enabling an event such as a telecollaboration or conference event in a communication network. The apparatus is tree-structured, and comprises a main site and one or more descendent sites, each site comprising one or more servers. Each site is a parent site, a descendent site, or both. Two sites may be connected via a dedicated or controlled connection. The apparatus further comprises client devices, each client device connecting to one site. The method of the disclosed invention comprises passing information between a client device and a server or between two servers exactly once. The information is propagated by each server to all the components connected to the server, i.e. the parent site if any, descendent sites if any, and client devices if any, excluding the component from which the server received the information.