Introduction

Quality of Service (QoS) features give you the ability to manage traffic intelligently across your enterprise network and optimize resource utilization.

These topics introduce you to QoS and the Cisco COPS QoS Policy Manager.

Quality of Service (QoS) is a set of capabilities that allow you to deliver differentiated services for network traffic, thereby providing better service for selected network traffic. For example, with QoS, you can increase bandwidth for critical traffic, limit bandwidth for non-critical traffic, and provide consistent network response, among other things. This allows you to use expensive network connections more efficiently, and to establish service level agreements with customers of the network.

To implement QoS, you define QoS policies for network devices. The policies can differentiate traffic based on categories, such as user address, application type, and so on.

If you have insufficient bandwidth, either due to the lines you are leasing or the devices you have installed, QoS can help you allocate guaranteed bandwidth to your critical users and applications. Alternatively, you can limit the bandwidth for non-critical applications (such as FTP file transfers), so that other applications or users have a greater amount of bandwidth available to them. For example, video applications require a certain amount of bandwidth for them to work in a usable manner. With QoS policies, you can guarantee the bandwidth required for these applications.
For time-sensitive applications, which are sensitive to timeouts or other delays, you can help the applications by coloring their traffic with higher priorities than your regular traffic, or by placing the traffic in a priority queue. You can also define minimum bandwidth to help ensure the applications can deliver data in a timely fashion.
SLA Management allows you to define strict minimum and maximum bandwidth limits to user groups and application groups based on pre-defined service level contracts between a user or customer, and a service provider.

On outbound device interfaces, packets can be queued according to their IP precedence (coloring). Using QoS, you can control how the queues are serviced, thus determining the priority of the traffic. As you deploy QoS, identify the applications and users on your network that are bandwidth or time sensitive, and also identify the applications that take more than their fair share of bandwidth. With this information, you can develop effective policies to improve the overall functioning of your network.

With Cisco's QoS Policy Management solutions you can define QoS policies for all types of network devices:

QPM-PRO provides provisioned QoS control using differentiated services to enforce QoS end-to-end. QPM-PRO's configuration interface allows you to define and deploy policies more easily than using device commands directly via the command line interface (CLI). QPM-PRO supports a broad base of Cisco devices and QoS features.
QPM-COPS supports newly emerging, standards-based technology for both signaled and provisioned QoS using the industry-standard COPS protocol. QPM-COPS complements the provisioning provided by QPM-PRO by allowing the definition and classification of user-based policies stored in a standard LDAP directory.

What Is COPS QoS Policy Manager?

COPS QoS Policy Manager (QPM-COPS) provides a scalable platform for defining and applying QoS policy. QPM-COPS manages QoS configuration and maintenance on a system-wide basis. QoS configurations are downloaded to network devices via the standards-based Common Open Policy Server (COPS) protocol.

These topics go into detail about the capabilities of QPM:

Overview of QPM-COPS

QPM-COPS lets you define and manage QoS configuration on a system-wide basis, thereby simplifying the task of maintaining consistent end-to-end device configuration. For example, you can define a set of three service levels and download them to every device on the network, thus ensuring consistent handling of packets throughout the network. Centralized management also allows you to make a single policy change and automatically download it to all the relevant devices in the QoS domain.

Using QPM-COPS, you can prioritize and control traffic for mission-critical applications, time-critical applications, and groups of users.

QPM-COPS supports both the Provisioning (Differentiated Services) approach and the Integrated Services (Signaling) approach for QoS management.

The Provisioning approach allows you to define scalable end-to-end provisioning policies to create differentiated services.

: With QPM-COPS, you first choose the set of end-to-end QoS services that you want to implement on the network. QPM-COPS includes several predefined service templates, each with a different set of QoS services. The set of services includes all configuration parameters needed to implement per-hop forwarding behavior, such as service levels, queueing mechanisms, and so on. Then you set classification and policing (limiting) rules on the boundary devices for specific data flows.

The Integrated Services approach enables RSVP applications to dynamically request and reserve network resources necessary to meet their specific QoS requirements, via the RSVP protocol. QPM-COPS lets you create RSVP policies to control the RSVP flows. QPM-COPS also supports an extension of RSVP, enabling end-host applications to signal higher-level parameters to the network. The Integrated Services approach is recommended for networks that have installed RSVP applications, such as NetMeeting.

QPM-COPS supports the COPS protocol for policy control, replacing the traditional Telnet configuration via the command line interface (CLI). COPS allows faster download times, and immediate identification of changes to devices' configuration and status. Provisioning policies are downloaded to devices using the COPS-Provisioning extension of the COPS protocol, and RSVP policies are downloaded using the COPS-RSVP extension of the COPS protocol.

QPM-COPS Components

Figure 1-1 shows the QPM-COPS components and architecture.

Figure 1-1: QPM-COPS Architecture

The QPM Server, Web servers, and QPM-COPS management applications all run on the central QPM server system. The default policy server (PDP) is also installed on the central QPM server. Additional servers can be installed on other remote systems.

The QPM Server handles the QoS policy database, and when requested, distributes the policies to the PDPs. The QPM Server also integrates with directory servers to:

Read user group information from CNR.
Export policy information, which can be used by the HP WebQoS application.

Policy Server (PDP)

The PDP is assigned to devices in the network, and communicates directly with its managed devices to implement the following policy management features:

Download provisioning policy statements to the devices using the COPS-PR flavor of the standard COPS protocol. The policy server (PDP) does not need to know anything about device interfaces. It simply knows that a device uses a certain set of roles, and then pushes those roles' policies to the device. The device makes the decision to implement QoS policies based on its own capabilities.
Respond to reservation requests made from the devices via the COPS-RSVP flavor of the standard COPS protocol. These responses are based on RSVP policies.

In addition, the PDP implements the following communication and control features:

Maintains a TCP connection with each of its managed devices based on the COPS protocol.
Maintains a connection with QPM server.
The PDP can be assigned to devices as a secondary PDP in case a primary PDP fails. In this case, the primary PDP's devices will attempt to connect with the secondary PDP.
Redirects a device to disconnect itself from the PDP and connect to an alternative PDP (roll-over process).

Management Applications

QPM-COPS includes the following management applications:

Policy Editor---This application is for creating and modifying roles and policies. You also manage your QoS databases through the Policy Editor.
Distribution Manager---This application distributes policies to the PDPs, and checks the status of the distribution process.
Device Configuration---This application allows you to configure devices for QPM-COPS. Configuration tasks include adding and importing devices into the QPM Device Configuration database, assigning a PDP to devices, and assign roles to interfaces. These configurations are applied to the device via SNMP.
Setup---This application allows you to define the initial system setups when QPM-COPS applications and services are first used. For example, you can select a global service template, which specifies global service level settings, before you begin to create and edit policies.
Policy Validation---This application allows you to validate the policies set on managed and virtual devices. You can also perform role validation. Validation results inform you of mismatches between the service template settings and device capabilities.

QPM-COPS Features

Table 1-1 lists the main features of QPM-COPS.

Table 1-1: QPM-COPS Features

Feature Description

Simple Policy Definition

You define policy actions and the filter for traffic to which the policy actions apply. Policy definitions are not addressed to specific devices or interfaces.

Implements Differential Service model

You define a set of end-to-end QoS services that you want to implement on the network. Policy definitions are downloaded to devices using the COPS-PR protocol.

Predefined Service Templates

QPM-COPS comes with six service templates which define sets of service and scheduling definitions for different types of network traffic combinations. You choose the service template that is appropriate for your network.

Implements Integrated Service model

QPM-COPS supports COPS-RSVP, which enables RSVP applications to dynamically request and reserve network resources necessary to meet their specific QoS requirements.

Integration with Cisco Network Registrar (CNR).

You can create user-based policies using groups defined in CNR. You import these groups into QPM-COPS via LDAP.

Integration with Directory Servers

The QoS database can be projected to a directory server via LDAP for use by other applications.

Multiple Device Import

You can import multiple devices into the QPM-COPS Device Configuration database simultaneously. You can use lists created in Cisco Resource Management Essentials (RME) application, or any text file.

Policy Validation

You can perform validation on managed and virtual devices to view the differences between policy definitions and device capabilities.

Policy Queries

You can search for any policies defined for the domain.

Feature	Description
Simple Policy Definition	You define policy actions and the filter for traffic to which the policy actions apply. Policy definitions are not addressed to specific devices or interfaces.
Implements Differential Service model	You define a set of end-to-end QoS services that you want to implement on the network. Policy definitions are downloaded to devices using the COPS-PR protocol.
Predefined Service Templates	QPM-COPS comes with six service templates which define sets of service and scheduling definitions for different types of network traffic combinations. You choose the service template that is appropriate for your network.
Implements Integrated Service model	QPM-COPS supports COPS-RSVP, which enables RSVP applications to dynamically request and reserve network resources necessary to meet their specific QoS requirements.
Integration with Cisco Network Registrar (CNR).	You can create user-based policies using groups defined in CNR. You import these groups into QPM-COPS via LDAP.
Integration with Directory Servers	The QoS database can be projected to a directory server via LDAP for use by other applications.
Multiple Device Import	You can import multiple devices into the QPM-COPS Device Configuration database simultaneously. You can use lists created in Cisco Resource Management Essentials (RME) application, or any text file.
Policy Validation	You can perform validation on managed and virtual devices to view the differences between policy definitions and device capabilities.
Policy Queries	You can search for any policies defined for the domain.

What Devices and Software Releases Are Supported?

COPS is a standards-based protocol, and will be supported on a wide range of Cisco devices and on some non-Cisco devices. The release notes for your version of QPM-COPS will provide up-to-date information on device support.

How Does QPM-COPS Interact with Other Network Management Products?

QPM-COPS interacts with other network management products as follows:

QPM-COPS is a plug-in to CD One and is accessed through the CiscoWorks2000 desktop. CD One should be installed on the system before QPM-COPS is installed. Some CD One services are required by the QPM-COPS system and need to be installed on that system (JRE, Web Server, and more).
HP's WebQoS (via CA SDK) can read policy definitions from the directory using LDAP.
QPM-COPS can import predefined address ranges from CNR, which can be used in filter definitions in policy statements. CNR writes the address range information into a directory, and QPM-COPS fetches the required information from the directory.

Table of Contents

Introduction