Abstract: The present invention concerns an exchange control method, wherein an old host exchange accommodating a remote switch unit or subscribers is adapted to be accommodated in a new host exchange, and its object is to allow call processing control to be performed by the new host exchange while making effective use of the resources of the old host exchange including the remote switch unit. The new host exchange and the old host exchange are connected in an interoffice configuration by a signaling link, and each exchange includes an emulation processor; the old host exchange and the new host exchange perform message editing and exchange between the respective emulation processors, and exchange control is performed in such a manner that when there occurs data or a request for basic control that is normally processed at the old host exchange, the data or request is transferred to the new host exchange, and the new host exchange processes the data or request and sends a notification to the old host exchange.

Abstract: Disclosed is an exchange system having an originating call restriction function comprising a unit for counting originating calls, a unit for counting incoming calls, a storage unit for storing a number (N.sub.o) or originating calls that can be accepted from accommodated subscribers (111) within a predetermined period, storage unit for storing a number (N.sub.i) of incoming calls that can be accepted within a predetermined period, and a unit for correcting the number of calls that can be accepted. The correction of the number of calls that can be accepted is effected by comparing the number (N.sub.i) of incoming calls that can be accepted and a number (N.sub.ai) of accepted incoming calls. When the difference between the number (N.sub.i) of incoming calls that can be accepted and the number (N.sub.ai) of accepted incoming calls is decreased below a predetermined value, the number (N.sub.o) of originating calls that can be accepted is decreased by a predetermined correcting value (.alpha.), and the number (N.