User Manual - Configuration Guide (Volume 3)

Chapter 3

Versatile Routing Platform

 

Congestion Management

Table QC-3-1Comparison table of congestion management policies

 

 

 

 

 

 

 

No. of

Advantages

Disadvantages

 

 

queue

 

 

 

 

 

 

 

 

 

 

 

 

 

1. All packets are treated equally, and the

 

 

 

 

arriving sequence of packets determines the

 

 

 

 

packet occupied bandwidth, delay and loss of

 

 

 

1.No configuration is needed, and easy

the packets.

 

 

 

2. It has no restriction on mismatched data

 

FIFO

1

to use.

source (for example, UDP packet sending),

 

2. Simple processing with less

while the mismatched data source will affect the

 

 

 

 

 

 

processing delay

bandwidth of the matched data source (for

 

 

 

 

example, TCP packet sending).

 

 

 

 

3. Delay of the real-time application that is

 

 

 

 

sensitive to time can not be ensured (for

 

 

 

 

example VoIP).

 

 

 

It provides absolute priority for the data of

1. Configuration is needed, and processing

 

 

 

different services, and delay is ensured

 

 

 

speed is slow.

 

PQ

4

for real-time applications (for example,

 

2. If the bandwidth for packets with higher priority

 

VoIP) that are sensitive to time. The

 

 

 

is not restricted, packets with lower priority may

 

 

 

packet of priority service has absolute

 

 

 

not acquire the bandwidth.

 

 

 

priority to occupy the bandwidth.

 

 

 

 

 

 

 

1. Bandwidth can be allocated in

 

 

 

 

proportion for the packets of different

 

 

CQ

17

services.

Configuration is needed, and processing speed

 

2. If no specific types of packets exist, the

 

is slow.

 

 

 

bandwidth can be increased

 

 

 

 

 

 

 

automatically for the existing packet

 

 

 

 

types.

 

 

 

 

1. Easy to configure.

 

 

 

 

2. The bandwidth can be protected for

 

 

 

 

coordinated (interactive) data source (for

 

 

 

Specified

example, TCP packet sending).

 

 

 

3. Capable of reducing the jitter of the

 

 

WFQ

by the user

delay.

The processing speed is slower than FIFO.

 

(256 by

4. Small packet is sent with priority.

 

 

 

 

 

default)

5. Different bandwidths can be allocated

 

 

 

 

for the flows with different priorities.

 

 

 

 

6. When the number of the flows is

 

 

 

 

reduced, the bandwidths for the existing

 

 

 

 

traffic can be increased automatically.

 

3.1.4 Working Principle of Congestion Management Policy

Normally, queuing technology is adopted to manage congestion. When congestion occurs, data packets queue up at the sending interface of the router following a certain policy. When the packets are dispatched, the sending sequence of the packets is determined following a certain policy.

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Huawei v200r001 user manual Working Principle of Congestion Management Policy, No. Advantages Disadvantages Queue