Alcatel-Lucent 7450 Quality Of Service Manual page 57

If the named pool policy is applied to an MDA or port that cannot create every pool defined
in the policy, the policy application attempt will fail. Any preexisting named pool policy on
the MDA or port will not be affected by the failed named pool policy association attempt.
When buffer pools are being created or deleted, individual queues may need to be moved to
or from the default pools. When a queue is being moved, the traffic destined to the queue is
first moved temporarily to a 'fail-over' queue. Then the queue is allowed to drain. Once the
queue is drained, the statistics for the queue are copied. The queue is then returned to the free
queue list. A new queue is then created associated with the appropriate buffer pool, the saved
stats are loaded to the queue and then the traffic is moved from the fail-over queue to the new
queue. While the traffic is being moved between the old queue to the fail-over queue and then
to the new queue, some out of order forwarding may be experienced. Also, any traffic
forwarded through the fail-over queue will not be accounted for in billing or accounting
statistics. A similar action is performed for queues that have the associated pool name added,
changed or removed. This only applies to where fail-over queues are currently supported.
The first step in allowing named pools to be created for an MDA is to enable 'named-pool-
mode' at the IOM level (config card slot-number named-pool-mode). Named pool mode may
be enabled and disabled at anytime. When MDAs are currently provisioned on the IOM, the
IOM is reset to allow all existing pools to be deleted and the new default, named MDA and
named port pools to be created and sized. If MDAs are not currently provisioned (as when the
system is booting up), the IOM is not reset. When named pool mode is enabled, the system
changes the way that default pools are created. The system no longer creates default pools per
port, instead, a set of per forwarding plane level pools are created that are used by all queues
that are not explicitly mapped to a named pool.
Quality of Service Guide
• Network pool
• The number of named per-port pools is dependent on the number of ports the MDA
supports which is variable per MDA type
• Per-port named pools cannot be used by ingress network queues, but pools defined
in a named pool policy defined on an ingress all network port are still created
→ Ingress network queues use the default network pool or MDA named pools.
→ Ingress port buffer space allocated to network mode ports is included in the
buffers made available to ingress MDA named pools.
→ Ingress port buffer space on channelized ports associated with network
bandwidth is included in the buffers made available to ingress MDA named
pools.
→ Ingress port named pools are only allocated buffers when the port is associated
with some access mode bandwidth.
• Per-port named pools on ports aggregated into a LAG are still created per physical
port
• Default, named MDA and named per-port pools are allocated regardless of queue
provisioning activity associated with the pool
QoS Policies
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