Alcatel-Lucent 7950 Quality Of Service Manual page 379

For policers, this command is used to configure the policer's PIR leaky bucket's high priority violate thresh-
old. The high-prio-only command is applied to the MBS value to derive the bucket's low priority violate
threshold.
For ingress, trusted in-profile packets and un-trusted high priority packets use the policer's high priority vio-
late threshold while trusted out-of-profile and un-trusted low priority packets use the policer's low priority
violate threshold. At egress, in-profile packets use the policer's high priority violate threshold and out-of-
profile packets use the policer's low priority violate threshold.
The PIR bucket's violate threshold represent the maximum burst tolerance allowed by the policer. If the
policer's offered rate is equal to or less than the policer's defined rate, the PIR bucket depth hovers around
the 0 depth with spikes up to the maximum packet size in the offered load. If the offered rate increases
beyond the metering rate, the amount of data allowed above the rate is capped by the threshold. The low pri-
ority violate threshold provides a smaller burst size for the lower priority traffic associated with the policer.
Since all lower priority traffic is discarded at the lower burst tolerance size, the remaining burst tolerance
defined by high-prio-only is available for the higher priority traffic.
The policer's mbs size defined in the QoS policy may be overridden on an sla-profile or SAP where the pol-
icy is applied.
The no form of this command
Default
64 kilobytes when PIR = max, otherwise 10ms volume of traffic for a configured non zero/non max PIR.
Parameters
size [bytes | kilobytes] — For queues, the size parameter is an integer expression of the maximum number
of bytes or kilobytes of buffering allowed for the queue. For a value of 100 kbps, enter the value 100. A
value of 0 causes the queue to discard all packets. For policers, the size parameter is an integer
expression of the maximum number of bytes for the policer's MBS. The queue MBS maximum value
used is constrained by the pool size in which the queue exists and by the shared pool space in the
corresponding megapool.
Values
Values
[bytes | kilobytes] — Select bytes or kilobytes. Kilobytes is the default.
packet-byte-offset
Syntax packet-byte-offset {add bytes | subtract bytes}
no packet-byte-offset
Context config>qos>qgrpid>ing>qgrp>queue
Description
This command is used to modify the size of each packet handled by the queue by adding or subtracting a
number of bytes. The actual packet size is not modified; only the size used to determine the ingress
scheduling and profiling is changed. The packet-byte-offset command is meant to be an arbitrary
mechanism that can be used to either add downstream frame encapsulation or remove portions of packet
headers. Both the scheduling and profiling throughput is affected by the offset as well as the stats
(accounting) associated with the queue. The packet-byte-offset does not apply to drop statistics, received
valid statistics, or the offered managed and unmanaged statistics used by Ingress Multicast Path
Management.
7950 XRS Quality of Service Guide
returns
the MBS size assigned to the queue to the value.
For queues: 0 — 134217728, default
For policers: 0 - 16777216, default
Page 379