atmIfTxCellMemoryThresholdTable 1.3.6.1.4.1.562.2.4.1.114.441

This attribute is a vector which indicates the size and three discard thresholds for transmit cell memory for this AtmIf. This attribute is not applicable, and is not displayed on CQC-based ATM FPs. Transmit cell memory used for storing ATM cells to be transmitted by connections under this AtmIf. It includes all cells in connections at the nrt-VBR or UBR service category. It includes cells in CBR or rt-VBR connections which are doing per-VC queueing. It does not include cells in CBR or rt-VBR connections which are allocated from the dedicated buffer for CBR common queuing or rt-VBR common queuing. The first value indicates the transmit cell memory size. It is the multiplication of the Lp/x Eng Arc Aqm/y txCellMemoryThreshold 0 attribute by the txCellMemoryPercentage attribute of this AtmIf. The current value of txCellMemoryUsage together with the vector of values in txCellMemoryThreshold 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.