Communication system and a private branch exchange to be used in such a communication system
AssigneeU.S. Philips Corporation
InventorGerardus M. J. Havermans
Life of this patent
Estimating the term…
Abstract
An integrated services communication system ISDN in which a plurality of ISDN supported terminal stations can be coupled to an S.sub.0 bus coupled to a private branch exchange, of which a maximum of 2 terminal stations can be active over B-channels. Them is proposed also to connect incompletely ISDN supported terminal stations to the S.sub.0 bus, which stations have many non-ISDN supported features, there being investigated on line cards which type of terminal station is connected. On the basis of a Terminal Endpoint Identifier (TEI) in a layer-2 message, either a standard ISDN protocol is handled from layer-2 onwards, or a firm-owned protocol.
Claims4
An integrated services digital network (ISDN) communication system comprising:
- a private branch exchange;
- a public network coupled to the private branch exchange;
- an ISDN supported terminal station coupled via a bus to the private branch exchange for communicating with the public network via the private branch exchange;
- and
- an incompletely ISDN supported terminal station coupled via the bus to the private branch exchange for communicating with the public network via the private branch exchange;
- said private branch exchange including switching means for switching between an ISDN standard message handling protocol for the ISDN supported terminal station and a firm-owned message handling protocol for the incompletely ISDN supported terminal station.
A private branch exchange included in a communication system based on an integrated services digital network (ISDN) coupled to an ISDN supported terminal station and an incompletely ISDN supported terminal station via a bus for communication with a public network, said private branch exchange comprising:
- standard messaging means for communicating with the ISDN supported terminal station via an ISDN standard message handling protocol;
- further messaging means for communicating with the incompletely supported ISDN terminal station;
- a memory including a standard layer-2 protocol address field;
- and
- switching means, responsive to a value of standard layer-2 protocol address field, for switching between said standard messaging means and said further messaging means.
Dependencies are inferred from the claim text.