A comparison of automatic protocol generation techniques

Due to the increasing complexity of applications and the availability of high speed networks classical protocols have become the main bottleneck in communication systems. Although tailored protocols are able to respond to the needs of a given application their development is expensive in terms of time and effort. An automatic protocogeneration environment is most desirable. Two approaches currently used are the stub compilation and the runtime adaptive techniques. We have studied these two approaches and the behaviour of the resulting tailored transport protocols. Relative performance comparisons and discussions about these two approaches are presented in this paper

Transport of video over partial order connections

A Partial Order and partial reliable Connection (POC) is an end-to-end transport connection authorized to deliver objects in an order that can differ from the transmitted one. Such a connection is also authorized to lose some objects. The POC concept is motivated by the fact that heterogeneous best-effort networks such as Internet are plagued by unordered delivery of packets and losses, which tax the performances of current applications and protocols. It has been shown, in several research works, that out of order delivery is able to alleviate (with respect to CO service) the use of end systems’ communication resources. In this paper, the efficiency of out-of-sequence delivery on MPEG video streams processing is studied. Firstly, the transport constraints (in terms of order and reliability) that can be relaxed by MPEG video decoders, for improving video transport, are detailed. Then, we analyze the performance gain induced by this approach in terms of blocking times and recovered errors. We demonstrate that POC connections fill not only the conceptual gap between TCP and UDP but also provide real performance improvements for the transport of multimedia streams such MPEG video