198 CHAPTER 5: PATH BUILDER S330 DIAGNOSTICS AND PERFORMANCE STATISTICSCBR ATM StatisticsATM cell statistics are cell counts since the last counter reset. On the ATM Statisticswindow, you can reset the counter by entering c. ATM statistics are displayed as alist rather than a table. The CBR T1-DSX and CBR E1 ATM Statistics screens displaythe following statistics:CBR virtual circuits must be present in the database in order to view thesestatistics.Total Cells Received—Total number of cells received over the virtual circuit.Total Cells Transmitted—Total number of cells transmitted over the virtualcircuit.Total Cell Pointer Errors—Number of cells dropped due to structure pointermismatches.Total Cells Lost—The difference between the number of cells transmitted and thenumber of cells received.Total Number of Buffer Underflows—Number of buffer underflows over thevirtual circuit.Total Number of Buffer Overflows—Number of buffer overflows over thevirtual circuit.Total out of Sequence Errors—Number of cells received with out-of-sequencenumber mismatch.Total CRC Errors—Number of cells received with uncorrectable sequence numberCRC error.Total OAM Cells Received—Number of OAM (Operations, Administration, andMaintenance) cells received over the virtual circuit. These cells carry OAMinformation used for network management.Total OAM Cells Transmitted—Number of Operations Administration andMaintenance (OAM) cells transmitted over the virtual circuit.Current Cell Status—Cell loss period count (for CBR use only).Data Bytes To (structured data ports only)—The data bytes to the cell bus. Usethis value to set the DBA Bits Mask CBR port parameter. In most cases, the defaultDBA Bits Mask (127) is appropriate. If you are experiencing problems with a CCScircuit, however, you can set the DBA Bits Mask to monitor different bits. Checkthe Data Bytes To value, and set the DBA Bits Mask to that value.When you check the data bytes, you must first make sure that the circuit is in anidle state (phone onhook). If you cannot access the equipment to see whether ornot the circuit is in idle, then check the data bytes for at least 30 seconds (aboutseven updates). If the Data Bytes To value remains the same for 30 seconds ormore, it is safe to assume that the circuit is in an idle state.
