H3C S5120-SI Series, Руководство по эксплуатации

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Congestion Management Configuration
When configuring congestion management, go to these sections for information you are interested in:
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Overview
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Congestion Management Configuration Methods
Overview
Congestion occurs on the interface where the arrival rate of packets is faster than the sending 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 Fair Queuing (WFQ), 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.