Serial interface controller residual bit errors

[admin_2]

We have an x21 serial interface connecting to a bpx frame-relay node.

The serial interface is amassing input and crc errors quite dramatically but we also notice that

on issuing command

#sh controller serial 0

the following output.

10241736 residual bit errors

(which is also incrementing)

Is this indicative of a card failure ??

[#2]

It can be a defective connector, cable or backcard problem, try to isolate the problem by replacing each component one-by-one. Make sure the cable lenght is under X.21 physical specifications.