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Chapter 5: Configuring the Switch through the Web Utility
QoS
24-Port 10/100 + 2-Port Gigabit Switch with Webview and Power over Ethernet
IP Precedence/DSCP
This switch supports several common methods of prioritizing layer 3/4 traffic to meet application requirements.
Traffic priorities can be specified in the IP header of a frame, using the priority bits in the Type of Service (ToS)
octet or the number of the TCP port. If priority bits are used, the ToS octet may contain three bits for IP
Precedence or six bits for Differentiated Services Code Point (DSCP) service. When these services are enabled,
the priorities are mapped to a Class of Service value by the switch, and the traffic then sent to the corresponding
output queue. Because different priority information may be contained in the traffic, this switch maps priority
values to the output queues in the following manner:
The precedence for priority mapping is IP Port Priority, IP Precedence or DSCP Priority, and then Default Port
Priority.
IP Precedence and DSCP Priority cannot both be enabled. Enabling one of these priority types will automatically
disable the other.
The switch allows you to choose between using IP Precedence or DSCP priority. Select one of the methods or
disable this feature.
Disabled. Disables both priority services. (This is the default setting.)
IP Precedence. Maps layer 3/4 priorities using IP Precedence.
IP DSCP. Maps layer 3/4 priorities using Differentiated Services Code Point Mapping.
Select Disabled, IP Precedence or IP DSCP from the drop-down menu.
Click submit to save the changes.
To select the configuration type, select IP Precedence or IP DSCP from the drop-down menu.
Click config to save the changes.
Figure 5-28: QoS - IP Precedence/DSCP