11

Chapter 11

Quality of Service (QoS)

76

C

HAPTER

11

Chapter 11

Quality of Service (QoS)

11.1

The QoS General Screen

Use this screen to enable or disable QoS, set the bandwidth, and select to have the Router

automatically assign priority to upstream traffic according to the IP precedence or packet length.

Click

Network Setting > QoS

to open the

General

screen.

Figure 35

Network Setting > QoS > General

Table 33

Network Setting > QoS > General

LABEL

DESCRIPTION

Active QoS

Select the check box to turn on QoS to improve your network performance.

You can give priority to traffic that the Router forwards out through the WAN interface.

Give high priority to voice and video to make them run more smoothly. Similarly, give

low priority to many large file downloads so that they do not reduce the quality of other

applications.

Traffic priority

will be

automatically

assigned by

Select how the Router assigns priorities to various upstream traffic flows.

•

None:

Disables auto priority mapping and has the Router put packets into the

queues according to your classification rules. Traffic which does not match any of

the classification rules is mapped into the default queue with the lowest priority.

•

Ethernet Priority:

Automatically assign priority based on the IEEE 802.1p priority

level.

•

IP Precedence:

Automatically assign priority based on the first three bits of the TOS

field in the IP header.

•

Packet Length:

Automatically assign priority based on the packet size. Smaller

packets get higher priority since control, signaling, VoIP, internet gaming, or other

real-time packets are usually small while larger packets are usually best effort data

packets like file transfers.

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11.2

The Queue Setup Screen

Use the

Queue Setup

screen to configure QoS queue assignment. Click

Network Setting >

QoS >

Queue Setup

.

Figure 36

Network Setting > QoS > Queue Setup

Table 34

Network Setting > QoS > Queue Setup

LABEL

DESCRIPTION

Status

This indicates whether the queue is active or not.

A yellow bulb signifies that this queue is active. A gray bulb signifies that this queue is

not active.

Name

This shows the descriptive name of this queue.

Interface

This shows the name of the Router’s interface through which traffic in this queue passes.

Priority

This shows the priority of this queue.

Weight

This shows the weight of this queue.

Rate Limit

This shows the maximum transmission rate allowed for traffic on this queue.

Modify

Click the

Edit

icon to edit the queue.

Click the

Delete

icon to delete an existing queue. Note that subsequent rules move up

by one when you take this action.

Chapter 11

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11.2.1

Edit a QoS Queue

Use this screen to configure a queue. Click the

Edit

icon next to a QoS queue.

Figure 37

QoS > Queue Setup: Edit

Table 35

QoS > Queue Setup: Edit

LABEL

DESCRIPTION

Active

Select to enable or disable this queue.

Name

Enter the descriptive name of this queue.

Interface

Select the interface of this queue.

Priority

Select the priority level of this queue.

The lower the number, the higher the priority level. Traffic assigned to higher priority

queues gets through faster while traffic in lower priority queues is dropped if the

network is congested.

Weight

Select the weight of this queue.

If two queues have the same priority level, the Router divides the bandwidth across the

queues according to their weights. Queues with larger weights get more bandwidth than

queues with smaller weights.

Rate Limit

Specify the maximum transmission rate (in

Kbps

or

%

) allowed for traffic on this queue.

11.3

The Class Setup Screen

Use this screen to add, edit or delete QoS classifiers. A classifier groups traffic into data flows

according to specific criteria such as the source address, destination address, source port number,

destination port number or incoming interface.

You can give different priorities to traffic that the Router forwards out through the WAN interface.

Give high priority to voice and video to make them run more smoothly. Similarly, give low priority to

many large file downloads so that they do not reduce the quality of other applications.

Chapter 11

Quality of Service (QoS)

79

Click

Network Setting >

QoS > Class Setup

to open the following screen.

Figure 38

Network Setting > QoS > Class Setup

Table 36

Network Setting > QoS > Class Setup

LABEL

DESCRIPTION

Add new Classifier

Click

this to create a new classifier.

Order

This is the order of the classifier.

Index

This is the index number of the classifier.

Status

This indicates whether the classifier is active or not.

A yellow bulb signifies that this classifier is active. A gray bulb signifies that this

classifier is not active.

From Interface

If the classifier applies to traffic coming in through a specific interface, it displays

here.

Classification

Criteria

This shows criteria specified in this classifier, for example the interface from which

traffic of this class should come and the source MAC address of traffic that matches

this classifier.

DSCP (Traffic Class)

Mark

This is the DSCP number added to traffic of this classifier.

802.1P/1Q Mark

This is the IEEE 802.1p priority level assigned to traffic of this classifier.

To Queue

This is the name of the queue in which traffic of this classifier is put.

Modify

Click the

Edit

icon to edit the classifier.

Click the

Delete

icon to delete an existing classifier. Note that subsequent rules

move up by one when you take this action.

Chapter 11

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11.3.1

Add/Edit QoS Class

Click

Add

new Classifier

in the

Class Setup

screen or the

Edit

icon next to an existing classifier to

configure it.

Figure 39

QoS > Class Setup: Add/Edit