Ericsson ECN330, User Manual

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Configuring the ECN330-switch
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6.14.2 Layer 3/4 Priority Settings
6.14.2.1 Mapping Layer 3/4 Priorities to CoS Values
The ECN330-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 ECN330-switch, and the traffic then sent to the
corresponding output queue.
Because different priority information may be contained in the traffic, the
ECN330-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.
6.14.2.2 Selecting IP Precedence/DSCP Priority
The ECN330-switch allows a choice between using IP Precedence or DSCP
priority. Select one of the methods or disable this feature.
Command Attributes
• 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.