Chapter 12 Quality of Service (QoS)
AX/DX/EX/PX Series User’s Guide
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The following table describes the labels in this screen.
12.5  QoS Classification Setup
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. For example, you can configure a classifier to select traffic from the 
same protocol port (such as Telnet) to form a flow.
You can give different priorities to traffic that the Zyxel Device forwards 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.
Click Network Setting > QoS > Classification Setup to open the following screen.
Table 89   Network Setting > QoS > Queue Setup > Add New Queue/Edit
LABEL DESCRIPTION
Active Click this switch to enable the queue.
Name Enter a descriptive name for this queue. You can use up to 32 printable characters except [ " ], [ 
` ], [ ' ], [ < ], [ > ], [ ^ ], [ $ ], [ | ], [ & ], or [ ; ]. Spaces are allowed.
Interface Select the interface to which this queue is applied.
This field is read-only if you are editing the queue.
Priority Select the priority level (from 1 to 8) of this queue.
The smaller 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 (from 1 to 8) of this queue.
If two queues have the same priority level, the Zyxel Device divides the bandwidth across the 
queues according to their weights. Queues with larger weights get more bandwidth than 
queues with smaller weights.
Buffer 
Management
This field displays Drop Tail (DT). Drop Tail (DT) is a simple queue management algorithm that 
allows the Zyxel Device buffer to accept as many packets as it can until it is full. Once the buffer 
is full, new packets that arrive are dropped until there is space in the buffer again (packets are 
transmitted out of it).
Rate Limit Specify the maximum transmission rate (in Kbps) allowed for traffic on this queue. If you enter 0 
here, this means there's no rate limit on this queue.
Cancel Click Cancel to exit this screen without saving.
OK Click OK to save your changes.