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Far End Block Errors Detected

I have a 2621XM Routrer connected to an MGX/RPM over a Channelized E1 - balanced WAN link. A single Frame Relay PVC is configured over the E1 link and terminates on the same end devices.

The 2621XM is advising "Far End Block Errors Detected" in it's "show controllers e1" output. No other errors are evident on the 2621XM's show controller or show interface command outputs. I do not have access to the MGX/RPM. However the administrators of the MGX/RPM have advised that they do not see any errors on either the MGX's E1 port or the RPM PVC interface.

Please help.


Re: Far End Block Errors Detected

FEBE... this is what they are..

Far-End Block Error. FEBE is a signal the remote end sends to indicate that

it has received DS3 or E1 frames with either Framing Errors (FERR) or C-bit

Parity Errors (CPERR). A block error is detected each time the calculated

checksum of the received data does not correspond to the control checksum

transmitted in the successive superframe. One block error indicates that one

superframe has not been transmitted correctly. No conclusion with respect to

the number of bit errors can be drawn from the block-error counter.

I'd check both ends that you do have control over and ensure that framing/line build out (cable length)/etc for any error or config issues.

More than not it's your provider. Have them check the following: problems

with noise, line build out, active repeaters, or other sources of errors for


Hope this helps,


Community Member

Re: Far End Block Errors Detected


Thanks for your prompt response. I'll follow up with your suggestions.

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