Browsing by Subject "Switching networks"

Filter results by typing the first few letters
Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    Analysis of continuous feedback Markov fluid queues and its applications to modeling Optical Burst Switching
    (IEEE, 2013) Yazıcı, Mehmet Akif; Akar, Nail
    Optical Burst Switching (OBS) has been proposed as a candidate technology for the next-generation Internet. In OBS, packets are assembled into a burst, and a burst control packet is sent in advance to inform and reserve resources at the optical nodes in the path of the burst. In this study, we analyze the horizon-based reservation scheme in OBS using Markov fluid queues. First, we provide a solution to continuous feedback Markov fluid queues, then we model the horizon-based reservation scheme as a continuous feedback Markov fluid queue and numerically study it. We provide numerical examples to validate our model and its solution technique as well as to obtain some insight on the horizon-based reservation mechanism. © 2013 IEEE.
  • Thumbnail Image
    ItemOpen Access
    Dynamic threshold-based assembly algorithms for optical burst switching networks subject to burst rate constraints
    (Springer, 2010-04-17) Toksöz, M. A.; Akar, N.
    Control plane load stems from burst control packets which need to be transmitted end-to-end over the control channel and furtherprocessed at core nodes of an optical burst switching (OBS) network for reserving resources in advance for an upcoming burst. Burst assembly algorithms are generally designed without taking into consideration the control plane load they lead to. In this study, we propose traffic-adaptive burst assembly algorithms that attempt to minimize the average burst assembly delay subject to burst rate constraints and hence limit the control plane load. The algorithms we propose are simple to implement and we show using synthetic and real traffic traces that they perform substantially better than the usual timer-based schemes.
  • Thumbnail Image
    ItemOpen Access
    Effect of number of burst assemblers on TCP performance in optical burst switching networks
    (IEEE, 2006-10) Gürel, Güray; Karasan, Ezhan
    Burst assembly mechanism is one of the fundamental factors that determine the performance of an optical burst switching (OBS) network. In this paper, we investigate the influence of number of burstifiers on TCP performance for an OBS network. An ns2-based OBS network simulator is developed for simulating the optical network. The goodput of TCP flows between an ingress and an egress nodes traveling through an optical network is studied for different values of the number of assembly buffers per destination. First, the losses resulting from the congestion in the core OBS network are modeled using a burst independent Bernoulli loss model. Then, a background burst traffic is generated to create contention at a core node in order to realize a burst dependent loss model. Simulation results show that for an OBS network employing timer-based assembly algorithm, TCP goodput increases as the number of burst assemblers is increased for both types of loss models. The improvement from one burstifier to moderate number of burst assemblers is significant (15-50% depending on the burst loss probability, processing delay and the TCP version), but the goodput difference between moderate number of buffers andperflow aggregation is relatively small, implying that a cost-effective OBS edge switch implementation should use moderate number of assembly buffers per destination for enhanced TCP performance. © 2006 IEEE.