000032425 001__ 32425
000032425 005__ 20190117192504.0
000032425 0247_ $$2doi$$a10.5075/epfl-thesis-1948
000032425 02471 $$2nebis$$a4071987
000032425 037__ $$aTHESIS
000032425 041__ $$aeng
000032425 088__ $$a1948
000032425 245__ $$aRenegotiable VBR service
000032425 269__ $$a1999
000032425 260__ $$aLausanne$$bEPFL$$c1999
000032425 300__ $$a275
000032425 336__ $$aTheses
000032425 502__ $$aMartin Hasler, Claude Petitpierre, Martin Potts, Fiorenzo Scaroni
000032425 520__ $$aIn this work we address the problem of supporting the QoS requirements for applications while efficiently allocating the network resources. We analyse this problem at the source node where the traffic profile is negotiated with the network and the traffic is shaped according to the contract. We advocate VBR renegotiation as an efficient mechanism to accommodate traffic fluctuations over the burst time-scale. This is in line with the Integrated Service of the IETF with the Resource reSerVation Protocol (RSVP), where the negotiated contract may be modified periodically. In this thesis, we analyse the fundamental elements needed for solving the VBR renegotiation. A source periodically estimates the needs based on: (1) its future traffic, (2) cost objective, (3) information from the past. The issues of this estimation are twofold: future traffic prediction given a prediction, the optimal change. In the case of a CBR specification the optimisation problem is trivial. But with a VBR specification this problem is complex because of the multidimensionality of the VBR traffic descriptor and the non zero condition of the system at the times where the parameter set is changed. We, therefore, focus on the problem of finding the optimal change for sources with pre-recorded or classified traffic. The prediction of the future traffic is out of the scope of this thesis. Traditional existing models are not suitable for modelling this dynamic situation because they do not take into account the non-zero conditions at the transient moments. To address the shortfalls of the traditional approaches, a new class of shapers, the time varying leaky bucket shaper class, has been introduced and characterised by network calculus. To our knowledge, this is the first model that takes into account non-zero conditions at the transient time. This innovative result forms the basis of Renegotiable VBR Service (RVBR). The application of our RVBR mathematical model to the initial problem of supporting the applications' QoS requirements while efficiently allocating the network resources results in simple, efficient algorithms. Through simulation, we first compare RVBR service versus VBR service and versus renegotiable CBR service. We show that RVBR service provides significant advantages in terms of resource costs and resource utilisation. Then, we illustrate that when the service assumes zero conditions at the transient time, the source could potentially experience losses in the case of policing because of the mismatch between the assumed bucket and buffer level and the policed bucket and buffer level. As an example of RVBR service usage, we describe the simulation of RVBR service in a scenario where a sender transmits a MPEG2 video over a network using RSVP reservation protocol with Controlled-Load service. We also describe the implementation design of a Video on Demand application, which is the first example of an RVBR-enabled application. The simulation and experimentation results lead us to believe that RVBR service provides an adequate service (in terms of QoS guaranteed and of efficient resource allocation) to sources with pre-recorded or classified traffic.
000032425 6531_ $$aQoS
000032425 6531_ $$aRenegotiable VBR
000032425 700__ $$0241904$$aGiordano Cremonese, Silvia$$g105252
000032425 720_2 $$0241098$$aLe Boudec, Jean Yves$$edir.$$g105633
000032425 8564_ $$s1657929$$uhttps://infoscience.epfl.ch/record/32425/files/EPFL_TH1948.pdf$$yTexte intégral / Full text$$zTexte intégral / Full text
000032425 909C0 $$0252453$$pLCA2$$xU10427
000032425 909CO $$ooai:infoscience.tind.io:32425$$pDOI$$pIC$$pthesis$$qDOI2$$qGLOBAL_SET
000032425 918__ $$aIC$$bSSC$$cISC
000032425 919__ $$aLCA2
000032425 920__ $$a1999-4-15$$b1999
000032425 970__ $$a1948/THESES
000032425 973__ $$aEPFL$$sPUBLISHED
000032425 980__ $$aTHESIS