Zte ZXR10 5900E Series Configuration Manual page 7

Chapter 1
Port QoS Configuration
Table of Contents
Port QoS Overview.....................................................................................................1-1
Configuring Port QoS .................................................................................................1-4
Maintaining the Port QoS .........................................................................................1-10
Port QoS Configuration Example..............................................................................1-14
1.1 Port QoS Overview
Introduction to Port QoS
In a traditional Internet Protocol (IP) network, all packets are processed without any
difference. Routers use the First In First Out (FIFO) policy to process packets and the
best-effort principle to transmit packets to destinations. However, the routers cannot
guarantee the performance such as packet transmission reliability, delay, and so on.
With the development of new applications in an IP network, users have more requirements
for service quality. The best-effort in a traditional IP network cannot meet the requirements
of applications. For example, in the VoIP service, if the transmission delay of packets is
too long, users cannot bear it. A feasible method to solve the problem is to provide the
Quality of Service (QoS) ability for the Internet.
QoS is used to provide different service qualities (such as providing a special bandwidth,
reducing the packet loss rate, delay, and delay jitter) in accordance with different
requirements of applications.
Port QoS Principle
The port QoS is an important part of the QoS function. It is a QoS sub-module configured
on the basis of ports. The main functions are as follows:
l
Traffic limit
The traffic limit function based on ports is to limit the traffic rate of this port. For the
traffic exceeding the committed rate, perform the following operations:
Drop or forward packets (Red packets are dropped, and yellow packets are
à
allowed by default.)
Modify the DSCP value of a packet.
à
Modify the drop priority. A packet with a higher drop priority will be dropped first.
à
The default priority is 3 for a red packet, 2 for a yellow packet, and 1 for a green
packet.
SJ-20150114102049-008|2015-01-15 (R1.0)
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