Search Results

  1. J. Huttunen, Measurements on Differentiation of Internet Traffic, Master's Thesis, Networking Laboratory, Helsinki University of Technology, 2005 (pdf)(bib)
    Abstract: The use of real-time applications in the packet networks is setting new requirements for the packet delivery. The current best-effort model in the Internet does not facilitate control over important characteristics such as delay, jitter and packet loss, which is needed for the proper operation of applications with real-time requirements. The main focus during the last years on providing QoS in IP networks has been in the area of the Differentiated Services (DiffServ) architecture. DiffServ provides the necessary tools for implementing better service to the Internet in a scalable way. Scalability is an essential requirement for all Internet services. DiffServ is a framework that describes the main components and mechanisms for realizing QoS. The framework gives quite a lot of freedom for how the implementation is done and what are the differentiation principles. This has created a lot of research and arguments about how the DiffServ network should be actually implemented.\ This thesis studies the differentiation issues in the DiffServ network. Differentiation in this work is based on the idea of separating tracec with different characteristics (e.g. UDP and TCP) into distinct forwarding classes. The first part of this work presents the motivation for application based differentiation and describes the DiffServ architecture as well as some other ways of providing QoS in the Internet. Also two well known DiffServ implementations for general purpose PC hardware will be presented. The last part of this work presents measurements that we have conducted in an isolated DiffServ network using ALTQ as the QoS engine. ALTQ/CBQ is used to provide a class based isolation among different traffic types.