DFM always monitors all the links and reports the ISDN links as down (which are down but we don't care - we only care when they come up and the serial goes down). If DFM is causing the links to come up, that is because the ISDN has not been configured properly, to ignore uninteresting traffic.
You need to go into DFM>Administration Console, then choose Edit>Polling and Thresholds, and then choose the Thresholds tab.
Once there, select Interface Groups>Backup, and on the right side of the screen choose Matching Criteria>Type.
Double click on that line under Value, and add *BRI*. The line should already say *ISDN*, so if it
does put the pipe symbol between them and make it look like this *ISDN*|*BRI*.
If the Type line is not there, use the bottom window and scroll down until you see that, then
highlight it and click on Enable.
