ATM device, subscriber system, communication system and backup method

摘要

A technology is disclosed to enable VP/VC on an ATM network to be backed up by using an ISDN line without presetting any detailed information regarding a backup VP/VC to be set on the ISDN line. An ATM switch A 30 is provided to establish the ISDN line connecting with an ATM multiplexer A 20 when any failure occurs in an ATM transmission path contacting with the ATM multiplexer A 20 . Negotiation is carried out with ATM multiplexer A 30 by using the established ISDN line so as to decide a channel characteristic of a backup VP/VC to be set on the ISDN line. Then, the ATM switch A 30 and the ATM multiplexer A 20 communicate with each other by using the backup VP/VC having the decided channel characteristic on the ISDN line.