ZyXEL P-663H-51 Mode D'Emploi

 Chapter 9 Quality of Service (QoS)

P-663H-51 User’s Guide

DSCP is backward compatible with the three precedence bits in the ToS octet so that non-
DiffServ compliant, ToS-enabled network device will not conflict with the DSCP mapping.

The DSCP value determines the forwarding behavior, the PHB (Per-Hop Behavior), that each 
packet gets across the DiffServ network. Based on the marking rule, different kinds of traffic 
can be marked for different kinds of forwarding. Resources can then be allocated according to 
the DSCP values and the configured policies.

Click Advanced > Quality of Service to open the screen as shown next. 

Use this screen to enable or disable QoS, and select a DSCP mark to use on all outgoing 
packets that do not match a QoS classification rule. 

Figure 48   Advanced > Quality of Service 

The following table describes the labels in this screen. 

DSCP (6 bits)

Unused (2 bits)

Table 34   Advanced > Quality of Service

Enable QoS

Select the check box to turn on QoS to improve your network performance. 
You can give priority to traffic that the ZyXEL Device 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. 

Select 
Default 
DSCP Mark

Select a DSCP mark to use on all outgoing packets that do not match a QoS 
classification rule. You can select a specific DSCP mark to use or have the ZyXEL 
Device automatically select a DSCP mark to use.

Save/Apply

Click this button to save the changes and have the ZyXEL Device start using them.