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PRI to BRI connectivity

Hi all,

             I have  facing the problem in branch site , we have branches connected to HO by lease line and the failover is ISDN . i have configured pri timeslot and dailer at HO also configured BRI and serial INT at branch site .but the problem is the failover not auto done after serial fails also the test dailing at branch site is ok but auto dailing is not possible .pls check the below branch and HO config if there is any error pls guide me .



Hall of Fame Super Silver

Re: PRI to BRI connectivity

Hello Mak,

please post the configuration in a text file not everyone can open that document

Hope to help


Hall of Fame Super Gold

Re: PRI to BRI connectivity


I see several things in your configuration that may be causing the issue:

- I see a dialer-group configured under the interfaces but I do not see a dialer-list configured. With no dialer-list there will be no "interesting traffic" and the ISDN will not activate.

- I do not see anything configured at the branch that tells the ISDN what number to dial, something like dialer map.

- When you configure the serial interface with backup interface it puts the BRI into a special standby state. The BRI will not activate (it will not initiate a call and it will not answer a call) unless there is a failure of the primary interface (serial in your case). So how are you attempting to test the BRI? If you shut down the serial interface the BRI will not activate (IOS assumes that if you shutdown you intended to stop communication and will not activate the BRI). So you need some real failure of the serial (unplug it or something) for the BRI to be able to activate (even for a test).



Community Member

Re: PRI to BRI connectivity

Hi Richard ,

           thanks for your needfull reply ,

               i have allerady configured dailer string at branch site and check the test call by shutdown the  modem.test call completed but auto failover not happened . if you have example config of HO and branch connectivity then pls share with me....



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