Demand test descriptions and error codes - Avaya Support

ATM-NTWK (ATM Network Error)
The “lost cells” error can help you diagnose cell underrun problems. When cell underruns
are accompanied by lost cells errors, the lost cells could have caused the underruns. But if
you have cell under runs without lost cells, it could indicate that the underruns were due to
network jitter instead. It is also possible that network jitter can cause both cell underruns
and lost cells, if the jitter is so severe it causes the cells to violate their traffic contract.
When accompanied by congestion or CLP errors, the congestion or CLP can be causing
the lost cells.
When accompanied by cell overrun errors, the cell overruns can be causing the TN2305 to
discard cells, which in turn can show up as lost cells.
Lost cells without other errors can indicate that cells are being corrupted, especially the
AAL1 sequence number.
In any case, consult your ATM network vendor about possible causes. Look for jitter (cell
delay variation), cell discard, and traffic policing.
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