Statistics Displays 21-13
Token Ring-Specific Stati st ics
●FCS Violations – is the number of frames received that have failed the Frame
Check Sequence (FCS) cyclic redundancy check (CRC).
●Copy Err or s – is the number of frames received with duplicate addresses.
●Trans Absences – is the number of five half-bit time transitions. The counter is
incremented every time transitions are not detected between SDEL and EDEL
in a repeated frame.
●Frequency Errors – is the number of frames received with signal frequency
proble ms.
●Frm with Aborts – is the number of frames that were ab orted in mid transmission.
●Act Mon Reg en – is the number of times the active monitor is lost and regen-
erated.
●No Retu rn Frms – is the number of frames that fail to return f rom around the ring
due to a timeout or reception of another frame.
●Underru ns – is the number of frames that were not accepted due to DMA (direc t
memory access) underrun errors.
●No Buff Avail – is the number of frames that could not be received/repeated due
to lack of buffer space.
●A/C Er rors – is the number of AMP and SMP MAC frames with AC (ARI/FCI)
equal to zero when an intervening AMP MAC frame was not received.