|
This paper gives a status report on signaling specifications for ATM networks, focusing on the activities of international standardization bodies like ITU-T and ETSI, and on the implementation agreements drafted by the ATM-Forum. It shows that for ATM networks, the envisaged signaling specifications--besides providing the basic signaling functions of call establishment and release known from current networks--will provide a powerful network support system for advanced ATM applications like multimedia co-operation, teleconsulting and telemonitoring, teleparticipation, etc. For these applications, sophisticated support functions will be specified, e.g. procedures for point-to-multipoint connections, modifications of connection characteristics, look-ahead functions, multiconnection calls, etc. Such signaling functions for ATM networks are currently specified by international standardization bodies. The work of these bodies can roughly be classified into three consecutive steps: (1) Signaling for `B-ISDN capability set 1'. These functions allow for the establishment and release of a simple ATM connection between two parties. They are the basis for all further specifications. The standardization work for `Capability Set 1' has been finalized in 1994. (2) Signaling for `B-ISDN capability set 2'. These functions provide for a powerful support system for multimedia and multiparty applications. The current standardization work focuses on these specifications. (3) Signaling for `B-ISDN capability set 3'. Currently, only some vague ideas exist for this 3rd capability set, e.g. related to integration between B-ISDN and `Intelligent Networks', or related to the integration of TV-distribution. This paper gives an overview of the available signalling protocols of capability set 1, and of the future extensions currently being specified.
|
