HP 2610-PWR - Manual (Page 205)

Quality of Service (QoS): Managing Bandwidth More Effectively
Preparation for Configuring QoS
Planning a QoS Configuration
QoS uses resources in a way that requires attention to rule usage when
planning a QoS configuration. Otherwise, there is an increased possibility of
oversubscribing resources, which means that at some point the switch would
not support further QoS configuration.
Prioritizing and Monitoring QoS Configuration Options
Plan and implement your QoS configuration in descending order of feature
importance. This helps to ensure that the most important features are
configured first. Also, if insufficient rule resources become a problem, this
approach can help you recognize how to distribute the desired feature
implementations across multiple switches to achieve your objectives. For
example, a given type of traffic may be of higher importance than other traffic
types you want to expedite by using QoS. In this case you should plan and
configure your QoS resource usage first for the most important traffic type
before configuring QoS resource usage for other traffic types. If insufficient
resources remain for all of the QoS implementation you want, try spreading
this implementation across multiple switches.
Policy Enforcement Engine
The Policy Enforcement engine is the hardware element in the switch that
manages quality-of-service and ACL policies, as well as other software fea­
tures, using the rules that you configure. Resource usage in the Policy Enforce­
ment engine is based on how these features are configured on the switch. For
the switches covered in this guide, the term “resources” refers to the Policy
Enforcement Engine resources available to that feature.
QoS Resource Usage and Monitoring
QoS configurations on the switches covered in this guide use rule resources
as shown in Table 6-8. (How many resources are actually available depends
on ACL usage as well.)
Table 6-8. QoS Rule Resource Usage
QoS Classifier Rules Used
TCP and UDP Qos 2 per TCP or UDP Application
Device Priority QoS 2 per IP Address
ToS IP-Precedence 8 rules total per switch if this feature is enabled
QoS
6-15