Alcatel-Lucent 7750 SR OS Service Manual page 255

Port scheduler operation using frame transformed rates — The port scheduler uses the frame based
rates to figure the maximum rates that each queue may receive during the within-cir and above-cir
bandwidth allocation passes. During the within-cir pass, a queue may receive up to its frame based
within-cir offered-load. The maximum it may receive during the above-cir pass is the difference
between the frame based within-pir offered load and the amount of actual bandwidth allocated during
the within-cir pass.
SAP and subscriber SLA-profile average frame overhead override — The average frame overhead
parameter on a sap-egress may be overridden at an individual egress queue basis. On each SAP and
within the sla-profile policy used by subscribers an avg-frame-overhead command may be defined
under the queue-override context for each queue. When overridden, the queue instance will use its
local value for the average frame overhead instead of the sap-egress defined overhead.
The no form of this command restores the average frame overhead parameter for the queue to the
default value of 0 percent. When set to 0, the system uses the packet based queue statistics for calcu-
lating port scheduler priority bandwidth allocation. If the no avg-frame-overhead command is exe-
cuted in a queue-override queue id context, the avg-frame-overhead setting for the queue within the
sap-egress QoS policy takes effect.
Default
0
Parameters
percent — This parameter sets the average amount of packet-to-frame encapsulation overhead
cbs
Syntax cbs size-in-kbytes
no cbs
Context config>service>epipe>sap>egress>queue-override>queue
config>service>epipe>sap>ingress>queue-override>queue
config>service>apipe>sap>egress>queue-override>queue
config>service>apipe>sap>ingress>queue-override>queue
config>service>fpipe>sap>egress>queue-override>queue
config>service>fpipe>sap>ingress>queue-override>queue
7750 SR OS Services Guide
As a special case, when a queue or associated intermediate scheduler is configured with a CIR-
weight equal to 0, the system automatically sets the queue's frame based within-cir offered-load
to 0, preventing it from receiving bandwidth during the port scheduler's within-cir pass.
• Frame based PIR — The frame based PIR is calculated by multiplying the packet to frame factor
with the queue's configured PIR and then adding the result to that PIR. If the queue PIR is set to
7500 octets and the packet to frame factor equals 0.1, the frame based PIR would be 7500 x 1.1
or 8250 octets.
• Frame based within-pir offered-load — The frame based within-pir offered-load is the portion of
the frame based offered-load considered to be within the frame based PIR. The frame based
within-pir offered-load is the lesser of the frame based offered-load and the frame based PIR. If
the frame based offered-load equaled 11000 octets and the frame based PIR equaled 8250 octets,
the frame based within-pir offered-load would be limited to 8250 octets. If the frame based
offered-load equaled 7000 octets and the frame based PIR equaled 8250 octets, the frame based
within-pir offered load would equal 7000 octets.
expected for the queue. This value is not used by the system for egress Ethernet queues.
Values
0.00 — 100.00
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