Alcatel-Lucent 7450 - Network Queue Parent Scheduler

QoS Scheduler Policies
Quality of Service Guide 517
Network Queue Parent Scheduler
Network queues support port scheduler parent priority-level associations. Using a port
scheduler policy definition and mapping network queues to a port parent priority level, HQoS
functionality is supported providing eight levels of strict priority and weights within the same
priority. A network queue’s bandwidth is allocated using the “within-cir” and “above-cir”
scheme normal for port schedulers.
Queue CIR and PIR percentages when port-based schedulers are in effect will be based on
frame-offered-load calculations. Figure 26 demonstrates port-based virtual scheduling
bandwidth distribution.
A network queue with a port parent association exists on a port without a scheduler policy
defined will be considered to be orphaned.
Figure 26: Bandwidth Distribution on Network Port with Port-Based Scheduling
Foster Parent Behavior for Orphaned Queues and Schedulers
All queues and schedulers on a port that has a port-based scheduler policy configured will be
subject to bandwidth allocation through the port-based schedulers. All queues and schedulers
that are not configured with a scheduler parent are considered to be orphaned when port-
based scheduling is in effect. This includes access and network queue schedulers at the SAP,
multi-service site, subscriber and port level.
By default, orphaned queues and schedulers are allocated bandwidth after all queues and
schedulers in the parented hierarchy have had bandwidth allocated “within-cir” and “above-
cir”. In essence, an orphaned scheduler or queue can be considered as being foster parented
by the port scheduler. Orphaned queues and schedulers have an inherent port scheduler
association as shown below:
• Within-CIR priority = 1
OSSG136
Network
Queue
(Packet Provisioned)
Rate Limiting
Port Priority
Level
(Frame Provisioned)
Rate Limiting
Port Scheduler
(Frame Provisioned)
Queue
Highest
Lowest
Weighted
Rate Limiting
Scheduler
Highest
Egress
Network
Port
Lowest
Strict
Priority
Rate Limiting
Scheduler