Alcatel-Lucent 7750 SR OS Interface Configuration Manual page 275

Description
This command defines the percentage or specifies the sum of the pool buffers that are used as a
guideline for CBS calculations for access and network ingress and egress queues. Two actions are
accomplished by this command.
It is important to note that this command does not actually set aside buffers within the buffer pool for
CBS reservation. The CBS value per queue only determines the point at which enqueuing packets are
subject to a RED slope. Oversubscription of CBS could result in a queue operating within its CBS
size and still not able to enqueue a packet due to unavailable buffers. The resv-cbs parameter can be
changed at any time.
If the total pool size is 10 MB and the resv-cbs set to 5, the 'reserved size' is 500 KB.
The no form of this command restores the default value.
Default
default (30%)
Parameters percent-or-default — Specifies the pool buffer size percentage.
slope-policy
Syntax slope-policy name
no slope-policy
Context config>port>access>egress>pool
config>card>mda>access>egress
config>card>mda>access>ingress
config>card>mda>network>egress
config>card>mda>network>ingress
config>port>access>egress>channel>pool
config>port>access>ingress>pool
config>port>network>egress>pool
Description
This command specifies an existing slope policy which defines high and low priority RED slope
parameters and the time average factor. The policy is defined in the config>qos>slope-policy
context.
7750 SR OS Interface Configuration Guide
• A reference point is established to compare the currently assigned (provisioned) total CBS with
the amount the buffer pool considers to be reserved. Based on the percentage of the pool reserved
that has been provisioned, the over provisioning factor can be calculated.
• The size of the shared portion of the buffer pool is indirectly established. The shared size is
important to the calculation of the instantaneous-shared-buffer-utilization and the average-
shared-buffer-utilization variables used in Random Early Detection (RED) per packet slope plot-
ting.
Values
0 — 100, default
Interface Configuration
Page 275