Repozytorium publikacji - Politechnika Gdańska

Current informational networks use a large variety of technologies to support data exchange. Most of them are focused on IP protocol and include mechanisms which by definition should supply demanded QoS. One of those mechanisms is efficient path calculation - routing. Traffic offered to the network can change very rapidly in short term. Routing should support such traffic changes and all the time calculate valid paths in terms of QoS constraints and optimal use of available resources. Using dynamic routing mechanisms causes also some consequences. The one is packet sequence changed order within single stream. Feasibility study on the subject proved that problem was never fully explained and verified in real network topologies. The paper presents problem definition and analysis. Simulation and analytical models have been proposed for DiffServ architecture with two queuing disciplines (PQ and WFQ with limited buffer sizes). Research scenarios were created on the base of real network topologies. The simulation results allowed explaining the effect and stating when the packet reordering should be taken into account while designing and maintaining network architectures. Analytic equations allowed estimating worst case scenario.

Autorzy

• Michał Czarkowski,
• dr hab. inż. Sylwester Kaczmarek link otwiera się w nowej karcie