Abstract: A communication system including a plurality of private directories containing information; and a plurality of public directory listings stored on a data network, each subscriber of the communication system having a private directory and at least one public directory listing, each public directory listing being configured to enable information requests for information from a target subscriber's private directory to be made by making requests to subscribers and to be reviewed by or on behalf of the target subscriber in order to determine what information, if any, will be supplied in response to the information request.

Abstract: A communication system, for A-Party Call Control comprising a Directory Storage from which data can be retrieved by an A-Party Device and for storing one or more directory entries for each Entity intended to be communicated with using the communication system, at least one of the one or more directory entries of each Entity associated with one or more Communication Identities, whereby an authorised A-Party Device seeking to request, establish, or maintain communication with a B-Party can obtain at least one Communication Identity for the B-Party, and a Communication Status Mechanism to enable an authorised A-Party Device to derive and confirm the current communications capabilities and one or more Effective Ring Timeout Parameters (RTPs) for at least one of said one or more B-Party Communication Identities and to determine whether there is at least one viable Effective RTP which can be employed to control an attempt to request, establish, or maintain communication with a B-Party.