Allied Telesis AT-9900 用户手册
Software Version 2.8.1
125
Software Version 2.8.1
C613-10477-00 REV B
C613-10477-00 REV B
QoS Enhancements
This Software Version includes the following enhancements to Quality of
Service:
Service:
■
■
This section describes the enhancements. The new and modified commands to
implement them are described in
implement them are described in
Port Groups
This enhancement introduces eight new commands and modifies two existing
show
show
commands for the AT-8948, x900-48, and AT-9900 switches.
A port group is a set of ports you have collected together so that QoS can
process them as a single entity. Typically, you create port groups and then
assign a policy to a group. When you do this, only one instance of the policy is
created. Traffic arriving via members of the port group is then processed by
that policy. If port groups are not used, when the policy is applied to multiple
ports, the policy’s configuration is copied and duplicated as multiple policies
in hardware.
process them as a single entity. Typically, you create port groups and then
assign a policy to a group. When you do this, only one instance of the policy is
created. Traffic arriving via members of the port group is then processed by
that policy. If port groups are not used, when the policy is applied to multiple
ports, the policy’s configuration is copied and duplicated as multiple policies
in hardware.
The distinction between multiple, different instances of a policy separately
attached to each port, and a single instance attached collectively to ports is
especially important for metering. Metering marks packets with a bandwidth
class number that indicates whether the packet is within specific bandwidth
limits. Downstream QoS processes then determine how to handle the packets,
depending on their respective bandwidth class. For individual ports, the
metering process separately measures the data rate coming into each port.
However, with port groups, metering collectively measures the total data rate
coming into members of the group.
attached to each port, and a single instance attached collectively to ports is
especially important for metering. Metering marks packets with a bandwidth
class number that indicates whether the packet is within specific bandwidth
limits. Downstream QoS processes then determine how to handle the packets,
depending on their respective bandwidth class. For individual ports, the
metering process separately measures the data rate coming into each port.
However, with port groups, metering collectively measures the total data rate
coming into members of the group.
A single port scenario is suitable for multiple unit situations, such as hotels,
where each port connects to a separate end-user, and you want to separately
meter data for each end-user. However, port groups are appropriate for
enterprises where all ports on a switch are connected to a LAN owned by one
customer. The goal is to measure the combined traffic arriving at the switch
over ports to which specific policies are assigned.
where each port connects to a separate end-user, and you want to separately
meter data for each end-user. However, port groups are appropriate for
enterprises where all ports on a switch are connected to a LAN owned by one
customer. The goal is to measure the combined traffic arriving at the switch
over ports to which specific policies are assigned.
Note that a port group cannot span across switch instances.
To create one or more port groups or remove a group, use the commands:
create qos portgroup
=
group-list [port=port-list]
[description=description]
destroy qos portgroup
=group-list
To add ports or remove them from a port group, use the commands:
add qos portgroup port
delete qos portgroup port
To attach a policy to a port group or remove the current policy, use the
command:
command:
set qos portgroup