|Research Unit in Networking|
1 Research unit in Networking, EECS department, University of Liège, Belgium
AbstractThe last ten years have seen a tremendous change in the communication environment. The changes in network performances have been at the origin of new protocols and of more efficient method of implementation. The changes in network service capability have raise the issue of offering, at the transport level, services available at the subnetwork or at the network level such as multicast service, synchronous service and broadband service. The changes in application requirements have introduced new requirements for communication. The Client/Server paradigm is looking for low latency, multimedia for low jitter and many applications are requesting bandwidth. The OSI project (ESPRIT II) has the basic goal to design a new transport service and a new transport protocol using a methodology based on LOTOS which will be used at the very beginning of the design process. The paper presents the services and the mechanisms which are presently under study. Services include a connection-mode, an unacknowledged connectionless-mode, an acknowledged connectionless-mode and a transactional connectionless-mode. We introduce the idea of a compulsory QoS value to achieve better defined transport service. Some of the transport protocol mechanisms are briefly presented; ACK on request from the sender, cumulative ACK with selective transmission, fast connect with an extension of the service, rate control instead of window-based flow control and use of transport management entities to support the compulsory QoS value.
Keywordsbroadband, high-speed networks, LOTOS, multimedia, OSI95, transport protocol, transport service
Editor: - G. Leduc -
Webmaster: - C. Soldani -
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