lp Eng Arc Tx Cell Threshold Table

This attribute is a vector which indicates the size and three discard thresholds for transmit cell memory for this FP. The transmit cell memory is used for storing ATM cells to be transmitted by this FP. The first value indicates the transmit cell memory size. This is derived based on the total transmit memory capacity of this FP, and the value of the connectionPoolCapacity and the txCellMemoryAllocation attributes. 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.