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isdn timer ?

i have a 1760 router with an isdn-bri interface which is a backup to a fr-connection.

when i reload the router, it needs a about 3 minutes to bring up the fr-line (bacause of fr lmi,..)

in that time the isdn-backup goes activ - this is what i do not want.

is there a possibility to configure a routers bri-interface, that after a routerreload the isdn is able to send pakets after for example 300 seconds (in that time the fr-link would be up)

thanks for answer!

Community Member

Re: isdn timer ?

You can use a backup delay timer, this will delay the bringing up of the ISDN line for a specified amount of time after it recognizes the loss of your primary line.

Router(config-if)# backup delay {enable-delay | never} {disable-delay | never}


Router(config-if)# backup delay 300 10

This would delay the ISDN line from coming up until after 5 minutes of the primary loss, than bring it back down after 10 seconds of the primary ling being restored. But, using 300 seconds would also delay the ISDN line from coming up whenever the primary line goes down, not just when the router is rebooted but always. Depending on what is carried on this Frame-Relay line would be impacted on the 5 minute length of time it takes to be restored by the ISDN line.

Hope this helps

J.Spinella, CCNP

Community Member

Re: isdn timer ?


thanks for answer - but this isn´t ok for us because we must go to backup just in 30 seconds bacause we transfer sna-traffic over xot - and the sna-session would be lost in case of 300 seconds.

so i am searching for an solution which delays the isdn to come up only in case of rebooting .

anyway thanks for answer

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