QoS and QoS Policies
132
Quality of Service Guide
3HE 11014 AAAC TQZZA Edition: 01
Note:
1. See Table 4 for a list of adapter cards and buffer sizes.
3.7.3 Service Egress QoS Policies
Service egress queues are implemented at the transition from the service network to
the service access network. The advantages of per-service queuing before
transmission into the access network are:
• per-service egress shaping, soft-policing capabilities
• more granular, more fair scheduling per service into the access network
• per-service statistics for forwarded and discarded service packets
The subrate capabilities and per-service scheduling control are required to make
multiple services per physical port possible. Without egress shaping, it is impossible
to support more than one service per port. There is no way to prevent service traffic
from bursting to the available port bandwidth and starving other services.
For accounting purposes, per-service statistics can be logged. When statistics from
service ingress queues are compared with service egress queues, the ability to
conform to per-service QoS requirements within the service network can be
measured. The service network statistics are a major asset to network provisioning
tools.
Service egress QoS policies define egress service queues and map forwarding class
flows to queues. In the simplest service egress QoS policy, all forwarding classes are
treated as a single flow and mapped to a single queue.
To define a basic service egress QoS policy, the following are required:
• a unique service egress QoS policy ID
• a QoS policy scope of template or exclusive
• at least one defined default queue. The parameters that can be configured for a
queue are discussed in Network and Service QoS Queue Parameters.
Flows Default FC One flow defined for all traffic:
• all traffic mapped to Best Effort (BE) with a low priority
Table 20 Default Service Ingress Policy ID 1 Definition (Continued)
Characteristic Item Definition
To Next Page
Loading...
