Basic Cos Configuration - NETGEAR GS108T-200NAS Software Administration Manual

GS108T and GS110TP Smart Switch Software Administration Manual
From the Class of Service link under the QoS tab, you can access the following pages:
• "Basic CoS Configuration" on page 4-2
• "CoS Interface Configuration" on page 4-4
• "Interface Queue Configuration" on page 4-5
• "802.1p to Queue Mapping" on page 4-7
• "DSCP to Queue Mapping" on page 4-9

Basic CoS Configuration

Use the Trust Mode Configuration page to set the class of service trust mode of an interface. Each
port in the switch can be configured to trust one of the packet fields (802.1p or IP DSCP), or to not
trust any packet's priority designation (untrusted mode). If the port is set to a trusted mode, it uses
a mapping table appropriate for the trusted field being used. This mapping table indicates the CoS
queue to which the packet should be forwarded on the appropriate egress port(s). Of course, the
trusted field must exist in the packet for the mapping table to be of any use, so there are default
actions performed when this is not the case. These actions involve directing the packet to a specific
CoS level configured for the ingress port as a whole, based on the existing port default priority as
mapped to a traffic class by the current 802.1p mapping table.
Alternatively, when a port is configured as untrusted, it does not trust any incoming packet priority
designation and uses the port default priority value instead. All packets arriving at the ingress of an
untrusted port are directed to a specific CoS queue on the appropriate egress port(s), in accordance
with the configured default priority of the ingress port. This process is also used for cases where a
trusted port mapping is unable to be honored, such as when a non-IP packet arrives at a port
configured to trust the IP DSCP value.
To display the Basic CoS Configuration page, click QoS  Basic  CoS Configuration.
4-2
v1.0, April 2010
Configuring Quality of Service