27 research outputs found
Pre-Congestion Notification Encoding Comparison
DiffServ mechanisms have been developed to support Quality of Service (QoS). However, the level of assurance that can be provided with DiffServ without substantial over-provisioning is limited. Pre-Congestion Notification (PCN) investigates the use of per-flow admission control to provide the required service guarantees for the admitted traffic. While admission control will protect the QoS under\ud
normal operating conditions, an additional flow termination mechanism is necessary in the times of heavy congestion (e.g. caused by route changes due to link or node failure).\ud
Encoding and their transport are required to carry the congestion and pre-congestion information from the congestion and pre-congestion points to the decision points. This document provides a survey of\ud
several encoding methods, using comparisons amongst them as a way to explain their strengths and weaknesses.\u
Methods for evaluation packet delay distribution of ows using Expedited Forwarding PHB, Journal of Telecommunications and Information Technology, 2004, nr 2
The paper regards problem of providing statistical performance guarantees for real-time flows using Expedited Forwarding Per Hop Behavior (EF PHB) in IP Differentiated Services networks. Statistical approach to EF flows performance guarantees, based on calculation of probability that end-to-end packet delay is larger than certain value, allows larger network utilization than previously proposed deterministic approach. In the paper different methods of packet delay distribution evaluation are presented and compared. Considered cases comprise evaluation of delay distribution models for the core network and evaluation of end-to-end packet delay in the network consisted of edge node and chain of core nodes. Results obtained with aid of analytical models are compared with simulation results
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EMERGE - ESnet/MREN Regional Science Grid Experimental NGI Testbed
This document is the final report on the EMERGE Science Grid testbed research project from the perspective of the International Center for Advanced Internet Research (iCAIR) at Northwestern University, which was a subcontractor to this UIC project. This report is a compilation of information gathered from a variety of materials related to this project produced by multiple EMERGE participants, especially those at Electronic Visualization Lab (EVL) at the University of Illinois at Chicago (UIC), Argonne National Lab and iCAIR. The EMERGE Science Grid project was managed by Tom DeFanti, PI from EVL at UIC
QoS in Node-disjoint Routing for Ad Hoc Networks
PhDA mobile ad hoc network (MANET) is a collection of mobile nodes that
can communicate with each other without using any fixed infrastructure.
It is necessary for MANETs to have efficient routing protocol and quality
of service (QoS) mechanism to support multimedia applications such as
video and voice.
Node-Disjoint Multipath Routing Protocol (NDMR) is a practical protocol
in MANETs: it reduces routing overhead dramatically and achieves
multiple node-disjoint routing paths.
Because QoS support in MANETs is important as best-effort routing is
not efficient for supporting multimedia applications, this thesis presents a
novel approach to provide that support.
In this thesis NDMR is enhanced to provide a QoS enabled NDMR that
decreases the transmission delay between source and destination nodes.
A multi-rate mechanism is also implemented in the new protocol so that
the NDMR QoS can minimise the overall delays. It is shown that these
approaches lead to significant performance gains. A modification to
NDMR is also proposed to overcome some of the limitations of the
original
Management qualitätsbasierter Gruppenkommunikation im Internet
Zugangs- und Nutzungskontrolle bei Unicast bedarf allein der
Überwachung am Netzeingang. Diese Arbeit entwirft das Verfahren DSMC (Diffserv Multicast), das die für Multicast zusätzlich benötigte Kontrolle im Netzinneren ergänzt. Es erweitert die Paketweiterleitung (MFC) der Router nur gering und ohne Eingriff in das Multicastrouting, unterstützt so alle Multicastroutingprotokolle des Internets und bietet eine skalierbare Signalisierung zur Steuerung durch zentrales Dienstgütemanagement
Estudio e implementación de mecanismos de calidad de servicio sobre una arquitectura de servicios diferenciados
Escueal Técnica Superior de Ingeniería de Telecomunicació