1st International ICST Workshop on Optical Burst/Packet Switching

Research Article

Effect of Number of Burst Assemblers on TCP Performance in Optical Burst Switching Networks

  • @INPROCEEDINGS{10.1109/BROADNETS.2006.4374326,
        author={Guray Gurel and Ezhan Karasan},
        title={Effect of Number of Burst Assemblers on TCP Performance in Optical Burst Switching Networks},
        proceedings={1st International ICST Workshop on Optical Burst/Packet Switching},
        publisher={IEEE},
        proceedings_a={WOBS},
        year={2006},
        month={10},
        keywords={},
        doi={10.1109/BROADNETS.2006.4374326}
    }
    
  • Guray Gurel
    Ezhan Karasan
    Year: 2006
    Effect of Number of Burst Assemblers on TCP Performance in Optical Burst Switching Networks
    WOBS
    IEEE
    DOI: 10.1109/BROADNETS.2006.4374326
Guray Gurel1,*, Ezhan Karasan1,*
  • 1: Department of Electrical and Electronics Engineering, Bilkent University, 06800 Ankara, Turkey
*Contact email: guray@ee.bilkent.edu.tr, ezhan@ee.bilkent.edu.tr

Abstract

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 and per- flow 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.