| 摘要 |
PURPOSE:To enable to introduce a PBX dial-in to an existing exchange network economically, by installing a PBX outgoing sender based on Link-by-link connection control system as a direct dial-in call to a PBX exchanger. CONSTITUTION:When a dial operation is made to callout from an outgoing telephone subscriber A to an incoming telephone subscriber B, a Forward signal is transmitted from an EX-A to an EX-B. The EX-B is an intracity exchanger where a PBX exchanger is allocated and provided with OS' and OGT' required for the call of the PBX dial-in calls. The Forward signal from the OS' is transmitted between the EX-B and the PBX. That is, the transmission and reception of signals between the EX-B and the PBX exchanger is executed between the EX-B and the PBX exchanger, allowing to avoid the effect to other EX-A and simplifying the signal system. |
