This attribute displays the number of errored verification frames
received during the test. A verification frame is considered to be
errored if it contains a recognizable verification frame header, but
does not match the transmitted frame bit for bit. (Thus, a
verification frame that returns after the succeeding verification
frame has been transmitted is considered to be errored.) The counter
wraps to zero if it exceeds its maximum value of (2**64)-1.
Note that the number of correct verification frames received during
the test can be computed by the expression verificationFrmRx -
verificationFrmBad.