ISDN BRI Layer1 down

[gmnavarro]

Hi,

I have got an RDSI movile link connected to a Cisco 2901 BRI interface. Every now and again the router shows me the port as layer1 down (not connected), although it is in deed.

The issue does not get resolved till I connect the RDSI movile link to an ARGUS (RDSI analyzator) and then plug it back to the BRI interface. Only then, layer1 is up again...

Any idea why this is happening?

Regards.

[paolo bevilacqua]

That is normal. When you make or recideve a call, it will come up again.

[gmnavarro]

Hi Paolo,

Well, I do not see it as normal. I have installed many of those ISDN Movile Links and never experienced such a behaviour. And the thing is that not seeing layer1 active, the CUCM will never lauch the call through that link as it appear on the MGCP gateway as not registered.

Could it be as voltage issue on the ISDN Movile Link side? How can I check that?

Regards

[paolo bevilacqua]

You can take debug bri and you will see the CO de-activating layer 1 after a timeout, and you can search te Internt to see how that is normal.

Due to that, ou should use H.323 or SIP for BRI, not MGCP.