Specifications

ExtremeWare XOS 10.1 Command Reference Guide 225
7 QoS Commands
This chapter describes the following commands:
• Commands for configuring Quality of Service (QoS) profiles
• Commands creating traffic groupings and assigning the groups to QoS profiles
• Commands for configuring, enabling and disabling explicit class-of-service traffic groupings (802.1p
and Diffserv)
• Commands for configuring traffic grouping priorities
• Commands for verifying configuration and performance
Qualify of Service (QoS) is a feature of ExtremeWare XOS that allows you to specify different service
levels for outbound and inbound traffic. QoS is an effective control mechanism for networks that have
heterogeneous traffic patterns. Using QoS, you can specify the service that a traffic type receives.
Policy-based QoS allows you to protect bandwidth for important categories of applications or
specifically limit the bandwidth associated with less critical traffic. The switch contains separate
hardware queues on every physical port. Each hardware queue is programmed by ExtremeWare XOS
with bandwidth management and prioritization parameters, defined as a QoS profile. The bandwidth
management and prioritization parameters that modify the forwarding behavior of the switch affect
how the switch transmits traffic for a given hardware queue on a physical port. Up to eight physical
queues per port are available.
To configure QoS, you define how your switch responds to different categories of traffic by creating and
configuring QoS profiles. The service that a particular type of traffic receives is determined by assigning
a QoS profile to a traffic grouping or classification. The building blocks are defined as follows:
• QoS profile—Defines bandwidth and prioritization parameters.
• Traffic grouping—A method of classifying or grouping traffic that has one or more attributes in
common.
• QoS policy—The combination that results from assigning a QoS profile to a traffic grouping.
QoS profiles are assigned to traffic groupings to modify switch-forwarding behavior. When assigned to
a traffic grouping, the combination of the traffic grouping and the QoS profile comprise an example of a
single policy that is part of Policy-Based QoS.
Extreme switch products support explicit Class of Service traffic groupings. This category of traffic
groupings describes what is sometimes referred to as explicit packet marking, and includes:
• IP DiffServ code points, formerly known as IP TOS bits