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Effective use of Quality of Service (QoS) capabilities requires careful planning. Before you deploy QoS to your network, carefully consider the types of applications used in the network and which QoS techniques might improve the performance of those applications. Then, use the Cisco COPS QoS Policy Manager (QPM-COPS) to create and deploy your QoS policies to the network.
These topics introduce you to QoS concepts, and get you started on developing a QoS strategy.
QPM-COPS supports QoS policies for both the differentiated services approach (provisioning), and the Integrated Services approach (RSVP or signaled QoS).
These topics cover the types of QoS capabilities you can implement with QPM-COPS.
QPM-COPS implements the differentiated services (DiffServ) approach to defining and applying QoS policies. In the DiffServ environment provisioning policies are pushed from the policy server (PDP) to the devices and not on demand as in the RSVP approach. When a device boots, it opens a COPS connection to its assigned PDP. Once the connection is established, the device queries the PDP and sends it configuration information. In response, the PDP downloads all provisioned policies assigned to that device. On receiving these policies the device maps them into its local QoS mechanisms.
Provisioning policies let you define the following:
In the integrated services (IntServ) approach, RSVP-enabled applications dynamically request and reserve network resources necessary to meet their specific QoS requirements.
RSVP-enabled applications signal the first hop device through a PATH message. The device forwards the PATH message to the PDP using the COPS-RSVP protocol. The PDP then decides whether to grant the RSVP request, and replies to the device with an accept or deny message. The device can then forward the RSVP PATH message.
Through proxy RSVP capabilities, devices can utilize RSVP to request resources on behalf of applications that are not yet RSVP-enabled.
A role contains a group of policies that will be implemented on a specified set of interfaces. The role is a label or identifier that is used to pass policy information between the PDP and its assigned devices. For example, you can create an Edge role that includes classification policies for data packets arriving at edge devices.
Service templates contain a set of QoS services including all configuration parameters needed to implement per hop forwarding behavior for each service level. The service template contains end-to-end service definitions, queueing preferences, and drop preferences for provisioning policies, as well as RSVP parameters for signaling policies.
QPM-COPS comes with a set of pre-defined templates. Each template provides QoS differentiation for different sets of traffic classes.
Service types define different types of classification for different types of traffic. For example mission-critical traffic requires different scheduling priority and bandwidth requirements than voice and video traffic. QPM-COPS comes with service templates that define various combinations of service types.
Queueing and drop preferences for a domain are defined in the service template. These definitions are downloaded to the devices, and when appropriate, each device applies the queuing or drop method that it supports. You do not need to know which queuing and drop methods each device supports.
QPM-COPS supports the following queuing techniques:
QPM-COPS supports the following DROP techniques:
This publication cannot cover everything you might want to know about quality of service. This section provides pointers to more information available on the web.
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The references are broken down into these categories:
Posted: Mon Jun 12 04:51:29 PDT 2000
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