At+t Corp.

Patrick H Fischer

Hossein Eslambolchi

Craig L DeCaluwe

Nicholas D De Trana

Joseph C Kohler

A method of detecting and recovering from an out-of-band signaling failure in a telecommunications network involves the reprogramming of switching centers to utilize existent inband signaling capabilities to temporarily replace the failed out-of-band capability. A processor of an originating switching center recognizes the loss of out-of-band signaling capability, determines impacted trunks and switches to in-band signaling from out-of-band signaling. In an alternative embodiment, the switch may use maintenance data bits of impacted trunks to initiate a call. The terminating switching center is programmed to receive and recognize the change in bit value of the signaling data and initiates well known processes to seize the trunk in memory, check continuity and receive dialed number data, preferably in the form of tones, over the seized trunk. The terminal switching center for the trunk then attempts to complete the call in accordance with the received dialed number data. Preferably, the in-band signaling system reverted to comprises multi-frequency (MF) address and E and M wink start supervisory signaling. At the conclusion of the out-of-band outage, the signaling characteristic is restored to out-of-band from in-band.

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Naperville, IL, United States of America

Patrick H Fischer