Browsing by Subject "sieć DiffServ"

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Access status: Open Access ,
Analytical models of selected DiiffServ network elements supporting assured forwarding
(Data obrony: 2007) Stankiewicz, Rafał
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
Analytical models of selected DiffServ network elements supporting Assured Forwarding (AF) service in a Differentiated Services (DiffServ) network are proposed in the dissertation. Simple analytical models for main network elements: meter/markers and droppers are provided. Models of the following meter/markers were proposed: Single Rate Three Color Marker (srTCM), Two Rate Three Color Marker (trTCM) and Time Sliding Window Three Color Marker (TSW3CM). Models for the following commonly used types of Multi-RED queues are developed: Weighted RED (WRED) and RED with In/Out and Coupled virtual queues (RIO-C). Both types of queues are scrutinized under two types of configuration of dropping thresholds: staggered and overlapped. Several mathematical methods, including the queuing theory and the probability theory, were used. Models of meter/markers are based the M/M/l/K and D/M/l/K queuing systems. Models of droppers are developed with the use of M(n)/M/1/K and M(n)/D/1/K queuing systems (systems with impatient customers). Since the models for DiffServ elements are independent of each other, they can be combined to model a more complex system. An example of such a model, supplemented by the model for a TCP throughput by the other author, is presented in the dissertation. Accuracy of the models is verified by simulations of a DiffServ network. Simulations were performed with ns-2 simulator.