Question : Problem: Deciphering sho int results in Cisco 1720 IOS 12.2

Hello,

I'm trying to troubleshoot a connection between two ISDN routers.  I have limited experience with Cisco so please be gentle.

The router in question has a FastEthernet Interface and two ISDN BRI's.  The router has 4 SPID's assigned to it.  When I do a sho int on the router I get the following:

BRI0 is up, line protocol is up
BRI0:1 up/up
BRI0:2 down/down

BRI1 up/up
BRI1:1 down/down
BRI1:2 down/down

BRI0 is connected to another 1700 at a satellite office and there are no isues with connectivity to and from.
BRI1 is also connected to another 1700 at another satellite office, but, I can only telnet from the main to the satellite.  I can't get from the satellite to the main.

Anyway, my question:

What is the 0:1, 0:2, etc thing?  Is this splitting the interface into "logical" interfaces?  How can I try to bring BRI1:1 back up?

TIA

Answer : Problem: Deciphering sho int results in Cisco 1720 IOS 12.2

BRI0 is the main interface, this will always be up/up as long as the ISDN line is plugged into it and it is working (even if no calls are active).

BRI0:1 and BRI0:2 are the "B" channels.  ISDN BRI has two B channels, hence the two "subinterfaces".  When a call is active, the first B channel (BRI0:1) will be brought up.  If you have multilink configured, the second B channel (BRI0:2) will come up as well and you'll be using both B channels for the call.  If no call is active, both channels will be down.

>How can I try to bring BRI1:1 back up?
You need to initiate a call either from the remote side or the main side to bring up the B channels.  To bring up the link, interesting traffic (defined by a dialer-list) must be configured on the router along with the proper static route and interface settings.