Browsing by Subject "congestion control"

Now showing 1 - 3 of 3

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 ,
Problemy wdrażania szerokopasmowych usług multimedialnych w heterogenicznych sieciach IP
(Wydawnictwa AGH, 2010/2011) Chodorek, Robert; Krempa, Agata; Pach, Andrzej R.; Chodorek, Agnieszka
For over 30 years of its existence, the Internet has evolved from traditional data networks in the largest multiservice networks. Some Internet service has been created from scratch (like e-mail), some of them (eg. television, or Internet telephony) is the adaptation of services previously implemented in specialized networks (broadcast television network, Plain Old Telephone Service - POTS, etc.). Implementation of new services is a complex issue. New services may interact with existing applications. Problems can also occur with services adapted from specialized networks - for example, due to much lower transmission quality than required. In this paper an analysis of contemporary services and requirements is described. We show problems, which occur due to the heterogeneity of multiservice network, as well as how to solve these problems.
Access status: Open Access ,
SARED: self-adaptive active queue management scheme for improving quality of service in network systems
(Wydawnictwa AGH, 2021) Adamu, Aminu; Surajo, Yusuf; Jafar, Muhammad T.
Considering the phenomenal growth of network systems, congestion remains a threat to the quality of the service provided in such systems, hence, research on congestion control is still relevant. The Internet research community regards active queue management (AQM) as an effective approach for addressing congestion in network systems. Most of the existing AQM schemes possess static drop patterns and lack a self-adaptation mechanism, as such they do not work well for networks where the traffic load fluctuates. This paper proposes a self-adaptive random early detection (SARED) scheme that smartly adapts its drop pattern based on a current network’s traffic load in order to maintain improved and stable performance. Under light- to moderate-load conditions, SARED operates in nonlinear modes in order to maximize utilization and throughput, while it switches to a linear mode in order to avoid forced drops and congestion under high-load conditions. Our conducted experiments revealed that SARED provides optimal performance regardless of the condition of the traffic load.