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Manage class of service, Cos configuration – NETGEAR MS510TXPP 8 Port Gigabit PoE Managed Switch User Manual

Page 191

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Smart Managed Pro Switches MS510TX and MS510TXPP

Configure Quality of Service

User Manual

191

Manage Class of Service

The Class of Service (CoS) queueing feature lets you directly configure certain aspects of
switch queueing. This provides the desired QoS behavior for different types of network traffic
when the complexities of 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

QoS > CoS > Advanced

menu, you can access pages that are described in the

following sections:

CoS Configuration on page

191

Configure Global CoS Settings on page

192

Configure CoS Interface Settings for an Interface on page

192

Configure the Global CoS Queue Settings on page

194

Configure the Global 802.1p to Queue Mapping on page

195

DSCP to Queue Mapping on page

196

CoS Configuration

Use the CoS 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 must be forwarded on the appropriate
egress port. Of course, the trusted field must exist in the packet for the mapping table to be of
any use. If this is not the case, default actions are performed. 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 cannot be honored, such as when a non-IP
packet arrives at a port configured to trust the IP DSCP value.