This document defines B-Frame Parity errors and explains how to get rid
There are no specific requirements for this document.
This document is not restricted to specific software and hardware
The information in this document was created from the devices in a
specific lab environment. All of the devices used in this document started with
a cleared (default) configuration. If your network is live, make sure that you
understand the potential impact of any command.
For more information on document conventions, refer to the
Technical Tips Conventions.
B-Frame Parity errors indicate an error in the header portion of the
frame. Errors in this portion of the frame mean that the routing information in
the frame has been corrupted, so the frame may not go to the correct
destination. For this reason, the frames are discarded.
The exact interpretation of B-Frame Parity errors varies slightly
between the cards that use the Xilinx-based BIF-RX and the Monarch cards that
use the SIMBA ASIC.
For the BIF-RX based cards, this error means that the first word had
an error in the horizontal parity. For the SIMBA, this error means either one
of the first four words had an error in the horizontal parity, or that the
intermediate, vertical parity BIP-16, that covers the first seven words, had an
They are errors on the point-to-point data path, so they fit into the
general category of debug. These errors are generally seen with BIP-16 errors
and can be anywhere from the BCC cross-point, backplane to the line or trunk
cards. Isolation is the difficult part with these errors, due to a long path
through multiple cards which is mostly entirely unique to a particular slot to
slot transmission. One needs to use all information available to minimize the
number of pieces of hardware that are suspect.
If multiple cards report the errors, there is a good chance that a
transmit path problem exists. One clue to the source might be a particular card
or port which does not show any errors, since it is less likely to send to