- ZyXEL VoIP Wi-Fi Phone User's Guide

P-2000W_V2 User’s Guide
104 Chapter 13 Administrator Web Configurator Screens
13.8 ToS
The second byte in an IPv4 packet is the Type of Service (ToS) byte. The first three bits (by
themselves) of the ToS byte are referred to as the IP Precedence bits and refer to a priority
from 0 to 7. The next three bits are used in conjunction with the IP Precedence bits to define
the Diffserv Code Point protocol (DSCP bits). The last two bits are reserved for future use.
13.9 Introduction to DiffServ
Quality of Service (QOS) mechanisms provides the best service on a per-flow guarantee. To
fine-tune the levels of services on the priority of the traffic flow using QoS places a heavy
burden on the network infrastructure.
DiffServ is a class of service (CoS) model that marks packets so that they receive specific per-
hope treatment at DiffServ-compliant network devices along the route based on the application
types and traffic flow. Packets are marked with DiffServ Code Points (DSCPs) indicating the
level of service desired. This allows the intermediary DiffServ-compliant network devices to
handle the packets differently depending on the code points without the need to negotiate paths
or remember state information for every flow. In addition, applications do not have to request
a particular service or give advanced notice of where the traffic is going.
Note: It is strongly recommended for better network performance that the settings are
left as per their defaults.
Figure 36 TOS/DIFFSERV
Table 22 TOS/DIFFSERV
LABEL DESCRIPTION
ToS/DiffServ (00~FF) Type the HEX code that represents the best method for data
transmission.
APPLY Click APPLY to save your changes without restarting the Prestige. Your
wireless LAN, Internet and SIP settings changes do not take affect until
you use RESTART (in the navigation panel).
CANCEL Click CANCEL to begin configuring this screen afresh.
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