Integrated Layer Processing of Complex Presentation

Application Level Framing (ALF) and Integrated Layer Processing (ILP) have been proposed as strategies for solving the end system bottleneck problem for modern, distributed applications. Distributed multimedia applications that employ software intensive coding and compression techniques appear to be likely performance beneeciaries of an ALF/ILP implementation approach. However, there is a widely held view that the computational complexity of such presentation protocol processing dwarfs any performance beneets that may be derived from ILP. This paper investigates the potential for ILP in a non-trivial distributed application: a JPEG photo server. We measure some of the potential beneets of ILP by instrumentation of the application and by some hand-coded integration experiments. Our results show that an ILP approach will be worthwhile for this application. Nonetheless, we also show that certain transformation stages may impose limits on the extent of loop integration. One of the drawbacks of ILP is its hand-coded approach and lack of modularity. We propose a strategy to further investigate ILP for complex applications that will utilise re-useable ""lter" components. This strategy will realise optimal performance, while also enabling automatic synthesis of communication modules to meet particular application requirements.