Overview Package Class Deprecated Help

Package slope

The XML API OSS interface uses the slope package to configure the RED slope characteristic associated with Network buffer policies. Network buffer policies determine the default buffer allocations for queues based on the queue forwarding class. (The RED slope characteristics define the buffers associated with the queues.)

Each buffer pool supports a high-priority and a low-priority RED slope. The high-priority RED slope manages access to the shared portion of the buffer pool for the high-priority or in-profile packets. The low-priority RED slope manages access to the shared portion of the buffer pool for low-priority or out-of-profile packets. By default, the high-priority and low-priority slopes are disabled.

A RED slope is a graph with an X (horizontal) and a Y (vertical) axis. The X-axis plots the percentage of shared buffer utilization, from 0 to 100%. The Y-axis plots the probability of packet discard marked from 0 to 1. The slope can be defined as four sections, as shown in the following diagram

RED slope characteristics

Section A is (0, 0) to (start-avg, 0). For this part of the slope, the packet discard value is always zero, which prevents the RED function from discarding packets when the shared buffer average utilization falls between 1 and start-avg.

Section B is (start-avg, 0) to (max-avg, max-prob). This part of the slope is a linear slope where packet discard probability increases from zero to max-prob.

Section C is (max-avg, max-prob) to (max-avg, 1). This part of the slope shows the increase of packet discard probability from max-prob to one. A packet discard probability of one results in an automatic discard of the packet.

Section D is (max-avg, 1) to (100%, 1). For this part of the slope, the shared buffer average utilization value of max-avg to 100% results in a packet discard probability of one.