lpEngArcAqmTxCellThreshTable
1.3.6.1.4.1.562.2.4.1.12.23.5.4.448
This attribute is a vector which indicates the size and three discard
thresholds for transmit cell memory for the ATM Queue Manager
(AQM) ASIC on this FP. Transmit cell memory is used for storing
ATM cells to be transmitted by connections. It includes all cells in
all connections at all service categories.
The first value indicates the transmit cell memory size. It is the
amount of transmit memory which is available for cell queueing,
after the amount of memory specified by connectionPoolCapacity.
The current value of txCellMemoryUsage together with the vector
of values in txCellMemoryThresholds determines the
txCellMemoryCongestionState. The congestion state determines
whether cells of a given discard priority (DP) are discarded or
queued for transmit.
When the txCellMemoryUsage attribute is between threshold 0 and
threshold 1, the txCellMemoryCongestionState indicates the value
0. In congestion state 0, traffic with DP > 0 is discarded. Threshold
1 is set approximately at 90 percent of threshold 0, the total transmit
cell memory size.
When the txCellMemoryUsage attribute is between threshold 1 and
threshold 2, the txCellMemoryCongestionState indicates the value
1. In congestion state 1, traffic with DP > 1 is discarded. Threshold
2 is set approximately at 85 percent of threshold 0, the total transmit
cell memory size.
When the txCellMemoryUsage attribute is between threshold 2 and
threshold 3, the txCellMemoryCongestionState indicates the value
2. In congestion state 2, traffic with DP > 2 is discarded. Threshold
3 is set approximately at 75 percent of threshold 0, the total transmit
cell memory size.
When the txCellMemoryUsage attribute is below threshold 3, the
txCellMemoryCongestionState indicates the value 3. In congestion
state 3, traffic with DP=3 is queued.