Number portability for a cluster of switches

摘要: To provide station number portability within a cluster of switches interconnected in communication switching network each switch the is provided with two translation tables stored main memory processor. When digits are dialled to connect another office code extracted and if this an any first table instructs that be carried out second table. The contains all numbers which relates these either physical line or instruction route switch. "ported" i.e., physically disconnected from one reconnected switch, minor change made retain portability.