Table 15: Supported Scheduler Policies - Alcatel-Lucent 7950 Quality Of Service Manual

QoS Policies
Virtual Hierarchical Scheduling
Virtual hierarchical scheduling is a method that defines a bounded operation for a group of queues.
One or more queues are mapped to a given scheduler with strict and weighted metrics controlling
access to the scheduler. The scheduler has an optional prescribed maximum operating rate that
limits the aggregate rate of the child queues. This scheduler may then feed into another virtual
scheduler in a higher tier. The creation of a hierarchy of schedulers and the association of queues
to the hierarchy allows for a hierarchical Service Level Agreement (SLA) to be enforced.
Scheduler policies in the routers determine the order queues are serviced. All ingress and egress
queues operate within the context of a scheduler. Multiple queues share the same scheduler.
Schedulers control the data transfer between the following queues and destinations:
•
•
•
•
There are two types of scheduler policies:
•
•
Schedulers and scheduler policies control the data transfer between queues, switch fabric
destinations and egress ports/interfaces. The type of scheduling available for the various
scheduling points within the system are summarized in

Table 15: Supported Scheduler Policies

Service Egress Queues
Network Egress Queues
Page 56
Service ingress queues to switch fabric destinations.
Service egress queues to access egress ports.
Network ingress queues to switch fabric destinations.
Network egress queues to network egress interfaces.
Single Tier Scheduling on page 57
Hierarchical Scheduler Policies on page 59
Scheduling From To
Access Egress Ports
Network Egress Interfaces
7950 XRS Quality of Service Guide
Table 15.
Single-Tier
Yes
Yes
Hierarchical
Yes
No