Figure 16: Two Scheduler Policy Model For Access Ports; Service Or Scheduler Child To Port Scheduler Parent - Alcatel-Lucent 7950 Quality Of Service Manual

Egress Port-Based Schedulers

Service or Scheduler Child to Port Scheduler Parent

The service
independent scheduler policy definitions while the independent schedulers receive bandwidth
from the scheduler at the port level. By using two scheduler policies, available egress port
bandwidth can be allocated fairly or unfairly depending on the desired behavior.
graphically demonstrates this model.
Queue
Queue
Queue
Queue
Queue
Queue
Once a two scheduler policy model is defined, the bandwidth distribution hierarchy allocates the
available port bandwidth to the port schedulers based on priority, weights, and rate limits. The
service
Due to the nature of the two scheduler policy, bandwidth is allocated on a per-service or per basis
as opposed to a per-class basis. A common use of the two policy model is for a carrier-of-carriers
mode of business. In essence, the goal of a carrier is to provide segments of bandwidth to
providers who purchase that bandwidth as services. While the carrier does not concern itself with
the interior services of the provider, it does however care how congestion affects the bandwidth
allocation to each provider's service. As an added benefit, the two policy approach provides the
carrier with the ability to preferentially allocate bandwidth within a service
service
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scheduler to port scheduler association model allows for multiple services
or
SAP or MSS
Strict/
Weighted
Rate Limiting
Scheduler
Strict/
Weighted
Rate Limiting
Scheduler
Rate Limiting
Strict/
Weighted
Rate Limiting
Scheduler

Figure 16: Two Scheduler Policy Model for Access Ports

level schedulers and the queues they service become an extension of this hierarchy.
or
level policy without affecting the overall bandwidth allocation to each service
or
Rate Limiting
Strict/
Weighted
Rate Limiting
Scheduler
Rate Limiting
Strict/
Weighted
Scheduler
Rate Limiting
7950 XRS Quality of Service Guide
Priority 1
Weighted
Scheduler
Priority 2 Port
Weighted Strict Rate
Limiting
Scheduler Scheduler
Priority n
Weighted
Scheduler
or
to have
or
Figure 16
Port
OSSG131
context through the
.
or