Browsing by Subject "DiffServ"

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Access status: Restricted ,
Analiza efektywności architektury DiffServ w zapewnianiu wysokiej jakości usług
(Data obrony: 2020-01-21) Kos, Kamil
Wydział Informatyki, Elektroniki i Telekomunikacji
Access status: Open Access ,
Congestion control in flow-aware networks
(2007-05-31) (Data obrony: 2009-06-29) Domżał, Jerzy
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
The congestion control mechanisms for Flow-Aware Networks are presented in the dissertation. The research was performed for four proposals, the EFM (Enhanced Flushing Mechanism), the RAEF (Remove Active Elastic Flows), the RBAEF (Remove and Block Active Elastic Flows) and the RPAEF (Remove and Prioritize in access Active Elastic Flows) mechanisms. The idea of all presented congestion control mechanisms is similar and relies on total or partial cleaning of the PFL (Protected Flow List) content in the MBAC (Measurement Based Admission Control) block in congestion. The main goal of the proposed solutions is to minimize the acceptance time of new streaming flows in FAN routers. The streaming transmission in FAN is proposed for low traffic consuming applications with demands on low packet delays and loss. The congestion control mechanisms for FAN, proposed in the dissertation are described in details and analyzed by simulation experiments run on the ns-2 simulator. The obtained results show the advantages of the new solutions. The second part of the dissertation presents the new proposal of realizing the FAN concept. In this solution, the algorithm for random dropping of packets from the queue in congestion is used. It is implemented based on the AFD(Approximate Fair Dropping) mechanism. The new proposal is less complex than two well known FAN versions.
Access status: Open Access ,
Wpływ kształtowania ruchu na opóźnienia w sieci IP w architekturze Usług Zróżnicowanych dla reguł przesyłania pakietów EF PHB
(2004-04-29) (Data obrony: 2010) Gozdecki, Janusz
Wydział Elektrotechniki, Automatyki, Informatyki i Elektroniki
The dissertation is the analysis of the benefits of traffic shaping using leaky bucket algorithm at the maximum delay in a network, which packets can suffer during transmission over an Differentiated Services (DiffServ) IP network. In the central part of the desideration, the author proposes to use hop-by-hop aggregate-based shaping to decrease delay bounds for network services based on EF PHB. Author's findings are important to understand how aggregate-based shaping can influence performance of DiffServ networks. In the dissertation delay bounds within the boundaries of a DiffServ network with hop-by-hop EF PHB aggregate leaky bucket shaping are considered. First a model of network architecture is derived. Based on this model author formulates a theorem which describes the end-to-end delay bound for EF PHB based services in a DiffServ network where hop-by-hop EF PHB aggregate leaky bucket shaping is applied. Author proves that the application of aggregate-based shaping in a general network architecture with FIFO Guaranteed Rate aggregate scheduling decreases the deterministic end-to-end delay bound for EF PHB based services in DiffServ networks. The statement is true when a service rate of EF PHB aggregate is lower than throughput of a link. Applying a leaky bucket shaping for flows aggregates in each node of the DiffServ domain avoids excessive jitter accumulation in the network.