Control arrangement for rerouting connections in telephone systems - derives. rerouting code signals from busy and clear back signals of minor exchanges

摘要

The telephone systems control circuit produces re-routing code signals if all connection paths between given equal ranking (private) branch exchanges are busy. The code signal for re-routing a connection if all direct lines between two eaul ranking branch exchangers are busy is derived from the busy signals of the connections in the first exchange. For re-routing between the second and a third branch exchange the re-routing code signal is derived from the clear back signal from the second exchange to the first exchange. The system uses a storage which holds data on the desired connection and allows checking of possible alternative connections before re-routing.