A Markov Chain Model for TCP NewReno Over Optical Burst Switching Networks

Study of the performance of transmission control protocol (TCP) over optical burst switching (OBS) networks has been an important problem of research lately. In this work, we propose an analytical model for a TCP NewReno source to derive the steady-state throughput in presence of burst assembly process and burst losses. The source model uses a Markov chain based evolution of congestion window and the network model characterizes the distribution of burst size for a general assembly process which is used to estimate the impact of a burst loss on the number of packets lost. A fixed-point iteration method is then used to jointly solve the source model and the network model to obtain the TCP send rate. We validate the proposed analytical model through simulations. Results highlight the importance of accounting for slow start and fast retransmit phases in the model.