We have a 2Mbit leased line between two of our sites. In the last day or two we have been experiencing thousands of frame and CRC errors on one of our serial interfaces (X21). Today our leased line providers did and end to end test of the line and found no problems. The router is a 1721 with a WIC card. The router is showing no other problems. Is the WIC card likely to be the problem and apart from replacing it is there any other information I could gather from the router that would confirm this?
Problem is the sites are 80 miles apart and because we have limited connectivity, its better than none, I've already ordered a new WIC-2T because we have another leased line out to the internet, so I would need a second WIC anyway. I suppose its just reassurance that its likely to be the WIC, fingers crossed as I've just commited ?500 to it with the cables!
To a point you can confirm it is the wic by placing a loop on the circuit at the csu/dsu toward the router.
This would mean all you had was wic-cable-csu/dsu-loop
If you own the CSU/DSU you can do this with software and can place it on the data side or line side of the csu/dsu. This would help to eliminate the csu/dsu. Otherwise you can loop it with a cable. It could still be the cdu/dsu and I tend to suspect those more than wic cards.
I did originally suspect the DSU but the engineers did there end to end test from our side of the dsu's, basically connected to the x21 interface on the dsu's at either end and plugged a gadget into it that then ran for about 30 mins
Just a quick update, I have now installed the WIC-2T and new cables. I have connected both lines, one 2Mbit to internet line and one 2Mbit point to point. The internet line is showing no errors on the interface whilst the point to point is still showing thousands within seconds of clearing the counters.
Attached is the output of a sh int s0
Could someone possibly just scan my configs please just to confirm I have no major blunder in there.
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