| 摘要 |
PURPOSE: A method for processing a CID(Caller Identification) call of a PBX(Private Branch Exchange) is provided to request a CID when a random caller without the CID requests a call to be received, and to call an extension subscriber only when the caller shows the CID, thereby protecting the extension subscriber. CONSTITUTION: A controller senses a local signal called with a ring group representative number through a local circuit(S11). If a No.7 receiving signal is sensed, the controller confirms whether a CID is included(S12). If not, the controller transmits a message requesting the CID to a local exchange(S13). If the message is received, the controller exactly analyzes the message, and decides whether the CID exists(S14). If so, the controller transmits a ring signal and the CID to a digital phone of an extension subscriber(S15). When a random receiver responds to the signal, the ring signal is released(S16).
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