CALL SETTING METHOD FOR HOUSING CHANGING SUBSCRIBER

摘要

PURPOSE: To perform call setting without setting a line by releasing a line resource between an exchange on a front stage and transmitting a call setting message when a transfer origin exchange receives a call originating request to a transferred subscriber. CONSTITUTION: A call setting request is issued first from a transmitter 1 to a receiver 4. A relay exchange 7 receiving a call setting request message 21 transmits a call setting request message 22 advancing a route 26. A subscriber exchange 5 receiving the message 22 transmits a release request message 23 including an identifier representing a housing changing subscriber to the relay exchange 7 on the front stage. The relay exchange 7 receiving the message 23, when identifying the fact that the housing of the receiver is changed to a transfer destination exchange from a received identifier, transmits a call setting request message 24 by selecting a route 27. A transfer destination subscriber exchange 6 receiving the message 24 transmits a call setting request message 25 to the housing changing subscriber.