On the Internet, a Quality of Service (QoS) guaranteed services are increasingly being demanded, and the Internet Engineering Task Force (IETF) is developing the specification documents for the QoS services intensively. This overview details the technical rationales underlining the contents of the specification documents developed by the IETF for Differentiated Services (DiffServ)--to provide QoS guarantee services in the large IP networks-- and Policy Framework--to manage DiffServ compliant networks. The IP networks with DiffServ consist of boundary routers and interior routers. These routers are composed of packet classifiers and marker, shaper, and policing function. Many vendors have developed DiffServ-compliant routers with gigabit interfaces. An example of an implementation of a DiffServ-compliant router and a demonstration of a QoS service using this router are presented here. The Policy Framework is expected to be one of the promising management solutions to co-operate with and manage many DiffServ-compliant routers. An experiment that adopts the Policy Framework to a DiffServ compliant network is also outlined.

Quality of service (QoS) technology has been implemented and started to be applied to new applications on the next-generation Internet. However, as new applications have many kinds of features and requirements, some additional features should be added to current QoS control technology. For example, they require a definition of a single policy to operate QoS control in the management domain consistently and efficiently. Policy definition for transport layer in a domain and among domains is being discussed at IETF to set a standard process, however detailed policy corresponding to the application or contents information according to the application semantics has not been discussed. Therefore we developed QoS policy control mechanism using metadata which is defined as a structured data according to the application semantics. Though metadata and transport mechanism can be located into quite different positions in the concept of network layers, we made them successfully collaborated by defining meta policy. In this paper, we describe our approach to define a meta policy based on the requirements and information contents from the application as a high level layer concept to be able to classify the network behavior. Our approach enables to multiple QoS control and collaboration among domains. We also report of the activities in IETF and ITU-T.