Automatic circuit back-up system

• US 5,515,418 A
• Filed: 04/27/1993
• Issued: 05/07/1996
• Est. Priority Date: 04/27/1992
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Totsuka, Yukako, Yamaguchi, Yasuhiro
• Primary Examiner(s): Chin, Stephen
• Assistant Examiner(s): LOOMIS, PAUL A
• Application Number:
  US08/052,996
• Time in Patent Office: 1,106 Days
• Field of Search: 379/133, 379/1, 379/2, 379/32, 379/34, 379/221, 379/229, 370/16, 370/13, 370/60, 370/94.1
• US Class Current: 379/32.04
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06
• CPC Class Codes: H04Q 11/0428 Integrated services digital network, i.e. systems for transmission of different types of digitised signals, e.g. speech, data, telecentral, television signals
• CPC Class Codes: H04Q 2213/1316 Service observation, testing
• CPC Class Codes: H04Q 2213/13166 Fault prevention
• CPC Class Codes: H04Q 2213/13167 Redundant apparatus
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13202 Network termination [NT]
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 ISDN
• CPC Class Codes: H04Q 2213/13216 Code signals, frame structure
• CPC Class Codes: H04Q 2213/13395 Permanent channel, leased line

Abstract

An automatic circuit back-up system is adapted to a data communication system including a private communication line for data communication and a back-up communication circuit for providing a back-up for the private communication circuit. The automatic circuit back-up system includes a periodic message transmitting circuit for transmitting a periodic message at a predetermined regular period to a distant office through the back-up communication circuit, and a monitoring circuit for monitoring whether the periodic message transmitted from the distant office via the back-up communication circuit is received at the predetermined regular period.

Claims

1. An automatic circuit back-up system for a data communication system, including a private communication line for data communication, a back-up communication line, and back-up communication circuits, with one back-up communication circuit located at a local office and one back-up communication circuit located at a distant office, each of said back-up circuits providing a back-up for said data communication system comprising:

periodic message transmitting means located at said distant office for periodically transmitting a message at a predetermined regular period to said local office through said backup communication circuit; and

monitoring means for monitoring whether said periodically transmitted message from said periodic message transmitting means at said distant office via said back-up communication circuit is received at said predetermined regular period, wherein a lack of detection of said periodically transmitted message indicates a possible failure of either said distant office back-up communication circuit or of said back-up communication line.

2. An automatic circuit back-up system as set forth in claim 1, wherein said back-up communication circuit is an integrated service digital network.

3. An automatic circuit back-up system as set forth in claim 2, wherein said periodic message transmitting means comprises a terminal adapter for calling control in the integrated service digital network and for signal conversion of data for the integrated service digital network.

4. An automatic circuit back-up system as set forth in claim 3, wherein information necessary for said period message is transmitted by setting in a calling party subaddress information area in a calling control information.

5. An automatic circuit back-up system located at a local office for a data communication system, including a private communication line for data communication, a back-up communication line, and back-up communication circuits, with one back-up communication circuit located at a local office and one back-up communication circuit located at a distant office, each of said back-up circuits providing a back-up for said data communication system, said system comprising:

failure detecting means for detecting either a failure in said private communication line, or a failure in a data circuit-terminating equipment, said data circuit-terminating equipment being located between equipment located at said local office and said private communication line;

data communication circuit switching means, said switching means being responsive to said failure detecting means detecting a failure, said switching means allowing for switching a data channel from said private communication line to said local office back-up communication circuit;

periodic message transmitting means for periodically transmitting a message at a predetermined regular period to said distant office back-up communication circuit; and

monitoring means for monitoring whether a message periodically transmitted from said distant office back-up communication circuit is received at a predetermined regular period, wherein a lack of detection of said message periodically transmitted from said distant office indicates a possible failure of either said distant office back-up communication circuit or of said back-up communication line.

6. An automatic circuit back-up system as set forth in claim 5, wherein said back-up communication circuit is an integrated service digital network.

7. An automatic circuit back-up system as set forth in claim 6, wherein said periodic message transmitting means comprises a terminal adapter for calling control in the integrated service digital network and for signal conversion of data for the integrated service digital network.

8. An automatic circuit back-up system as set forth in claim 7, wherein information necessary for said period message is transmitted by setting in a calling party subaddress information area in a calling control information.