Allied Telesis AT-S62 - Manual (Page 257)

AT-S62 Menus Interface User’s Guide
Section II: Advanced Operations 257
Note that the switch can only perform error checking of parameters and
parameter values for the policy and its traffic classes and flow groups
when the policy is set on a port.
QoS Policy
Guidelines
❑ A classifier may be assigned to many flow groups. However,
assigning a classifier more than once within the same policy may
lead to undesirable results. A classifier may be used successfully in
many different policies.
❑ A flow group must be assigned at least one classifier but may have
many classifiers.
❑ A flow group may only be assigned to one traffic class.
❑ A traffic class may have many flow groups.
❑ A traffic class may only be assigned to one policy.
❑ A policy may have many traffic classes.
❑ A policy may be assigned to many ports.
❑ A port may only have one policy.
❑ You can create a policy without assigning it to a port, but the
policy will be inactive.
❑ A policy must have at least one action defined in the flow group,
traffic class, or the policy itself. A policy without an action is
invalid.
❑ The switch can store up to 64 flow groups.
❑ The switch can store up to 64 traffic classes.
❑ The switch can store up to 64 policies.
Packet
Processing
The switch’s QoS tools can be used to perform any combination of the
following functions on a packet flow:
❑ Limiting bandwidth
❑ Prioritizing packets, to determine the level of precedence the
switch will give to the packet for processing
❑ Replacing the VLAN tag User Priority, to enable the next switch in
the network to process the packet correctly
❑ Replacing the TOS precedence or DSCP value, to enable the next
switch in the network to process the packet correctly.