Juniper JUNOSE 11.1.X - QUALITY OF SERVICE CONFIGURATION GUIDE 3-21-2010, Руководство по настройке

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2 node. Each line module supports a maximum of 64,000 nodes or queues per line
module.
Line modules with the TFA ASIC hardware provide 96,000 descriptors that are shared
between all nodes and queues. Each line module supports a maximum of 64,000
nodes or queues.
Related Topics
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To identify the type of ASIC used by a line module, see the ERX Module Guide
and the E120 and E320 Module Guide
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Scaling Subscribers on the TFA ASIC with QoS on page 128
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For more information about system resource requirements for shadow nodes,
see Managing System Resources for Shadow Nodes on page 151
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For information about egress memory available on ASIC line modules, see
Memory Requirements for Queue and Buffers on page 19
Scaling Subscribers on the TFA ASIC with QoS
The TFA ASIC on the ES2 10G LM supports a total of 32,000 nodes; however, it
requires that each queue stack above a node at both level 1 and level 2, and it cannot
skip a level in the scheduler hierarchy. The FFA ASIC also requires that each queue
stack above a node at both level 1 and 2, but it also offers more nodes, so the
scheduler hierarchy requirement is not as visible. The EFA ASIC does not require
queues to stack above any level.
Because the TFA ASIC cannot skip a level in the hierarchy and also offers a smaller
amount of nodes, scaling subscribers for triple-play configurations can exhaust node
resources. For example, the ethernet-default QoS profile specifies both an IP and a
VLAN node. Configuring 16,000 IP over VLAN subinterfaces consumes all 32,000
nodes, with no node resources remaining for other traffic-class groups. By carefully
configuring queues on the TFA ASIC, you can scale up to 16,000 subscribers for
multiple traffic-class groups in a triple-play configuration.
To conserve nodes on the TFA ASIC, you could apply one of the following
configurations:
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If the configuration includes IP and VLANs, you can configure shapers within
those queues to control service throughout. For example, in a triple-play
environment with voice, video, and data service, you might want to limit the
overall rate of traffic using a shared shaper.
At the same time, you might want to individually restrict the maximum rate of
each of the services. To conserve node usage, attach shapers to the queue for
each service, and attach the shared shaper to the best-effort queue. These queues
must be at level 3 in the scheduler hierarchy. Typically, aggregation nodes such
as an S-VLAN are placed at level 2. The VLAN queues then feed in to the S-VLAN
nodes, which then feed to the level 1 nodes below.
If you do not create a QoS hierarchy with queues at level 3, the system adds
phantom nodes to enforce this requirement. To display the hierarchy that is
created for the subscriber on the line module, issue the
show qos
scheduler-hierarchy command.
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Scaling Subscribers on the TFA ASIC with QoS
JUNOSe 11.1.x Quality of Service Configuration Guide