3Com 3CRDSF9PWR manual Service

13	CONFIGURING QUALITY OF
	SERVICE

Quality of Service (QoS) provides the ability to implement QoS and priority queuing within a network. For example, certain types of traffic that require minimal delay, such as Voice, Video, and real-time traffic can be assigned a high priority queue, while other traffic can be assigned a lower priority queue. The result is an improved traffic flow for traffic with high demand. QoS is defined by:

■Classification — Specifies which packet fields are matched to specific values. All packets matching the user-defined specifications are classified together.

■Action — Defines traffic management where packets to be forwarded are based on packet information, and packet field values such as VLAN Priority Tag (VPT) and DiffServ Code Point (DSCP).

■VPT Classification Information — VLAN Priority Tags (VPT) are used to classify packets by mapping packets to one of the egress queues. VPT to Queue assignments are user-definable. Packets arriving untagged are assigned a default VPT value, which is set on a per-port basis. The assigned VPT is used to map the packet to the egress queue.

This section contains information for configuring QoS, and includes the following topics:

■Viewing CoS Settings

■Defining CoS

■Defining the Queue Mode

■Viewing CoS to Queue Mapping

■Defining CoS to Queue Mapping

■Viewing DSCP to CoS Mapping

■Configuring DSCP to CoS Mapping

■Configuring Trust Settings

■Viewing Bandwidth Settings

■Defining Bandwidth Settings

■Configuring Voice VLAN