Providing relative services in IP routers

Abstract

Because of the development of the Internet and the price descrease of fast connections like ADSL or cable connections, new applications appear on Internet like streaming applications ( video on demand for instance). These kinds of application have more equirements and can't work correctly with the default service used today inside the IP routers : first arrived, first served service. This thesis focus on the relative services and shows how these services can be used to meet all new application requirements. Because application requirements can be usually expressed in terms of loss, delay or bandwidth, it 's possible to provide several levels of services (i .e. clasees of service) that allow delay or loss sensitive applications to work correctly. The different levels of services can be achieved by using delay and loss differentiation. Delay differentiation allows to priviledge some packets inside the router (the time that some packets passed inside a queue can be tuned) while loss differentiation allows to determine which packet must be discarded first in case of congestion. Because TCP is mainly used in the Internet, it's also possible to provide bandwidth differentiation by combining the two previous differentiations. This thesis also contains an important discussion about the implementation of such
mechanisms inside a FreeBSD based router using ALTQ and several experiments are done to validate this implementation

Date of Award	2001
Original language	English
Supervisor	Olivier Bonaventure (Supervisor)