Robust packet multicast service over a satellite link
The aim of this thesis is to investigate and understand the issues involved in using multicast communications over a non-reliable satellite link and to suggest suitable methods to improve multicast services when used on packet networks. Point-to-multipoint communications have been used for distribution of data. These are mainly found on circuit switched networks where there is bandwidth allocation, ensuring a good transmission link. However, as packet switched networks become more evolved due to their interesting properties of being able to share the available bandwidth, multicast communication is increasingly employed. A satellite link in a packet network is often used to provide connection to remotely located hosts. To use point-to-multipoint communications, especially for real-time applications, across a satellite link, a scheme employing Forward Error Correction (FEC) is presented. The scheme uses an XOR (Exclusive-OR) coding technique to generate the redundancy. It adjusts the rate of coding according to the varying condition of the link. By using this transmission strategy, the proposed scheme is implemented at the transport and the data link layer to enhance multicast communication services. In recent years, there has been a tremendous growth in the number of local and wide area networks. To manage these networks, it is necessary to monitor and analyse the network traffic regularly. Many commercially available analysers are either too expensive or too complicated. Perhaps the greatest setback lies in their presentation of vital information to the users in the form of screen after screen of textual data. Thus, it may require someone of experience to be able to fully understand the situation on the network and this, only after a detailed study of the data. The thesis investigates and proposes a new method of processing and presenting the information that will enhance the flexibility and productivity in the process of network troubleshooting.