3Com 3CRDSF9PWR-US - OfficeConnect Managed Fast Ethernet PoE..., Руководство пользователя

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13
C
ONFIGURING
Q
UALITY OF
S
ERVICE
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