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New Member

ISDN Backup

Hi all

The branch office of my company have no backup line and i need to implement it.

Actually we have VPN using ADSL and PIX 506 on each office (Central and branch).

Could you suggest me your preferred ISDN backup system for this scenario?

I´m looking for buy two Cisco 837 and two Cisco 801 and use HSRP but i think that this protocol is no compatible with 801 ISDN routers

Thanks in advance




Re: ISDN Backup

Hola Miguel,

HSRP is supported on the 801 starting with IOS release 12.1(3)XG, so you are likely to be ok with your 801 routers.

As with regard to the exact configuration of your backup, what device (if any) do you have in front of the PIX ? Basically, you would need to create a secondary VPN between the 801 and the PIX, and by configuring HSRP between the 837 and the 801, traffic would traverse either VPN, depending on the availability. You also might want to set up interface tracking (where you track the ISDN interface on the 801 and the ATM interface on the 837), in order to detect a WAN failure, and have HSRP act accordingly.

Let me know if you need help with the setup and configuration details.



New Member

Re: ISDN Backup

Hola GNT

Thank you for your response.

In front of my PIX i´ve an ADSL router provided by Telefonica (my TELCO company) In next days i will replace it for a brand new 837 in both locations.

I´ll try your suggestion and i´ll imform you if i success.


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