Studies of heterogeneous packet switched networks

Sammanfattning: Internet is a packet switched heterogeneous network. Much research can be done in order to learn about the properties of and extend the capabilities of the Internet. In this thesis three studies around this topic are presented. First study: proportional loss rate differentiation is a quality of service problem where network traffic are divided into classes, and each class receives a loss rate proportional to another class. Simulations are used to show that robust proportional loss rate differentiation can be obtained by using a relatively simple algorithm. Second study: the use of IPv4 options are often suggested to be used for extending the basic IPv4 protocol. Measurements are performed by sending sample packets show that the use of IPv4 options is problematic. Use of options leads to higher delay, although the difference is small. Furthermore, the jitter and loss rate increases. While the increased delay and jitter may be tolerable, the increased loss rate is probably not. Third study: merging Internet technologies, such as network address translation, mobile IP, firewalls etc., indicates that the Internet architecture is insufficient for current needs. The split naming/forwarding network architecture, is a network architecture intended to be simple and flexible. This architecture is described and it is argued that it is an interesting alternative to the current Internet architecture.