3Com 2916-SFP User Guide - Page 142

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 are 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 ■ Viewing CoS to Queue ■ Defining CoS to Queue ■ Viewing DSCP to Queue ■ Configuring DSCP Queue ■ Configuring Trust Settings ■ Viewing Bandwidth Settings ■ Defining Bandwidth Settings ■ Defining Voice VLAN