Cisco 2811 and line protocol

[blubomber]

I have a 2811 at one of our remote properties. I have a point to point T1 going from the main office to the remote location. I also have a 2811 at the main location. The 2811 at the main location keeps telling me that the line protocol on the T1 is down but the cable is connected. Oh, and the T1s are connected to the routers via internal csu/dsu cards. Some times the connection will be ok for a few hours then go down due to the line protocol being down.

So, what could be the causes for the line protocol to be down. I have called the T1 provider and they say everything is fine on thier end.

Also, what is the max distance a router can be from the T1 box? How long can the shielded cable be going from the T1 box to the WIC card?

Thank you for any help.

 

[Nazgulero]

Hello,

for X.21, V.35, and EIA/TIA-449 cables, the maximum distance is 50 feet (15 meters). If your cable is within specs, you might want to check if it is running along something that could cause electromagnetic interference.
In my experience, providers most of the time say that the problem is not on their side. I would turn on debugging (debug serial interface) and check if you miss keepalives from the remote end, which would prove that the problem actually is at the provider´s side.

Regards,

GP

 

[JOAMON]

I had a problem with new 2811 router an T1 cards. 2811 uses the new Wic-1DSU-T1-V2 cards and I needed three for point to point T1 connections. Installed three new cards and only card in first slot worked. Found that all cards would work in first slot but only 1 would work in all slots properly. Went thru three more cards with TAC to get 2 that would function in all slots. The V2 T1 cards are somewhat buggy and the cards may be what is giving you problems. Also check to see if one end is configured as clock source internal as T1 providers do not usually clock point to point connections and must be done with CPE equipment.