Congestion Management Configuration; Overview; Congestion Management Policies - H3C S5810 Series Operation Manual

6

Congestion Management Configuration

When configuring hardware congestion management, go to these sections for information you are
interested in:

Overview

Congestion Management Configuration Methods
Per-Queue Configuration Method
Overview
Congestion occurs on an interface when the traffic arriving rate is greater than the transmit rate. If there
is no enough buffer capacity to store these packets, a part of them will be lost, which may cause the
sending device to retransmit these packets because of timeout, deteriorating the congestion.
The key to congestion management is defining a dispatching policy for resources to decide the order of
forwarding packets when congestion occurs. Congestion management involves queue creation, traffic
classification, packet enqueuing, and queue scheduling.

Congestion Management Policies

In general, congestion management adopts queuing technology. The system uses a certain queuing
algorithm for traffic classification, and then uses a certain precedence algorithm to send the traffic. Each
queuing algorithm deals with a particular network traffic problem and has significant impacts on
bandwidth resource assignment, delay, and jitter.
Queue scheduling processes packets by their priorities, preferentially forwarding high-priority packets.
In the following section, Strict Priority (SP) queuing, Weighted Round Robin (WRR) queuing, and
SP+WRR queuing are introduced.
SP queuing
SP queuing is specially designed for mission-critical applications, which require preferential service to
reduce the response delay when congestion occurs.
6-1