Concepts

Before using quality of service (QoS), you need to learn the basic terminology and QoS concepts. These concepts help you determine whether the service meets your needs.

To carry out QoS, you configure policies using wizards in iSeries™ Navigator. A policy is a set of rules that designate an action. The policy basically states which client, application, and schedule (that you designate) must receive a particular service. You can ultimately configure the following policy types:

• Differentiated service

• Integrated service

• Inbound admission

Differentiated service and integrated service are considered outbound bandwidth policies. Outbound policies limit data leaving your network and help control system load. The rates you set within an outbound policy control how and what data is or is not limited within the system. Both outbound policy types might require a service level agreement (SLA) with your Internet service provider (ISP).

Inbound admission policies control the connection requests coming into your network from some outside sources. Inbound policies are not dependent on a service level from your ISP. To decide which policy you need to use, evaluate the reasons why you want to use QoS and consider the role of your system.

One of the most important parts of carrying out QoS is the operating system itself. You not only need to understand the QoS concepts, but also need to be aware of the role that your operating system plays in these concepts. The i5/OS^® operating system can only act as a client or a server, not as a router. For example, your operating system acting as a client can use differentiated service policies to ensure that information requests to other systems are given higher priority through the network. Your operating system acting as a server can use an inbound admission policy to limit Uniform Resource Identifier (URI) requests accepted by the server.

• Differentiated service
  This is the first type of the outbound bandwidth policy that you can create on your operating system. Differentiated service divides your traffic into classes. To carry out a differentiated service policy, you need to determine how you want to classify your network traffic and how to handle the different classes.

• Integrated service
  The second type of the outbound bandwidth policy that you can create is an integrated service policy. Integrated service provides the capability for IP applications to request and reserve bandwidth using the ReSerVation Protocol (RSVP) and quality of service (QoS) APIs.

• Inbound admission policy
  The inbound admission policy is used to control the connection requests coming into your network.

• Class of service
  When you create a differentiated service policy or an inbound admission policy, you also create and use a class of service.

• QoS APIs
  This topic contains information about protocols and APIs, and contains requirements for a router that is enabled for the ReSerVation Protocol (RSVP). The Quality of Service (QoS) APIs include the RAPI API, the qtoq socket API, the sendmsg() API, and the monitor APIs.

• Directory server
  You can export your policies to a directory server. Read this topic to see the Lightweight Directory Access Protocol (LDAP) concepts and configuration as well as the quality of service (QoS) schema.

Parent topic:

Related concepts
Service level agreement