Cos; Cos Configuration - NETGEAR XS728T ProSAFE Software Administration Manual

CoS

The Class of Service (CoS) queueing feature lets you directly configure certain aspects of
switch queueing. This provides the desired QoS behavior for various types of network traffic
when the complexities of Differentiated Services (DiffServ) are not required. The priority of a
packet arriving at an interface can be used to steer the packet to the appropriate outbound
CoS queue through a mapping table. CoS queue characteristics that affect queue mapping,
such as minimum guaranteed bandwidth, or transmission rate shaping are user-configurable
at the queue (or port) level.
Eight queues per port are supported.
From the CoS menu under the QoS tab, you can access the following:
•

CoS Configuration

• CoS Interface Configuration
• Interface Queue Configuration
• 802.1p to Queue Mapping
• DSCP to Queue Mapping
CoS Configuration
Use the CoS Configuration screen to set the Class of Service global trust mode. This global
setting is applied to each port in the switch to trust one of the packet fields (802.1p or IP
DSCP), or to not trust a packet's priority designation (untrusted mode). This mapping table
indicates the CoS queue to which the packet must be forwarded on the appropriate egress
ports. The trusted field must exist in the packet for the mapping table to be of any use, so
default actions are 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
ports, 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 configure global CoS settings:

1. Select QoS > CoS > Basic > CoS Configuration.
2. From the Global Trust Mode menu, specify whether to trust a particular packet marking at
ingress.
Global Trust Mode can be only one of the following:
• Untrusted. Do not trust any CoS packet marking at ingress.
XS728T ProSAFE 28-Port 10-Gigabit L2+ Smart Switch
Quality of Service
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