Project Description

  • Token-Ring LAN

    Simulation modeling and performance analysis of networks including traditional local networks such as token-ring and high-speed networks such as FDDI have been conducted.

    The token-ring local area network protocol (IEEE 802.5) was simulated using CSIM, a process oriented simulation language based on C. The model behavior was analyzed and its and its performance was compared with an analytical model. The effect of buffer size and service schemes on the network performance was studied.

    Analytical and simulation models for studying the effect of integrated traffic (voice and data) on a token-ring network have been developed which can be extended to video traffic as well. The model provides the selection of optimum voice packet length, maximum number of voice stations that the network can support, relationships between voice packet delay and number of voice stations and between voice and data traffic in the same network, and statistical characteristics of voice packet delay. This can be used as practical design rules for implementing multimedia integrated services using existing technology and standards.

    A dynamic protocol for token-ring network with unbalanced load conditions was designed by selecting the value of token_holding_time according to the load (or the queue length) at the node. This achieved both fairness in and better performance in terms of reduced waiting delay and buffer occupancy.

    For Details See the Relevant Publications

  • G. Edwards, R. Sankar, and P. Roth, CSIM Simulation of a Token Ring LAN , Transactions of the Society for Computer Simulation, Vol. 9, No.1, pp. 39-58, March 1992.
  • G. Edwards and R. Sankar, Modeling and Simulation of Networks using CSIM, SIMULATION, Vol. 58, No.2, pp. 131-136, Feb. 1992.
  • R. Sankar and G. Edwards, Effect of Service Schemes and Buffer Size on Token Ring Network Performance, Proc. ISMM International Symposium MICRO '90, Montreal, Canada, May 1990.
  • P. Roth and R. Sankar, Token-Ring Network - A Comparative Simulation Study, Proc. 21st Pittsburgh Modeling and Simulation Conference, Pittsburgh, PA, May 1990.
  • G. Edwards, Modelling and Performance Analysis of Token Ring Network, M.S. Thesis, November 1988.
  • R. Sankar and J. Murphy, Experiences in Local Networking USF, Proc. 15th IEEE Conf. on Local Computer Networks, Minneapolis, MN, October 1990, pp. 137-142.
  • W. Li and R. Sankar, Real-Time Voice and Data Integration in Token Ring LAN, Proc. IEEE Southeastcon '93, Charlotte, NC, April 1993.
  • W. Li, Voice and Data Integrated Service Token Ring Network, M.S. Thesis, December 1991.
  • R. Sankar and S. Varada, Dynamic Protocol for Token Ring Network with Unbalanced Load, Proc. IEEE Southeastcon '92, Birmingham, AL, April 1992, pp. 10-13.

  • FDDI

    Simulation modeling and performance analysis of networks including traditional local networks such as token-ring and high-speed networks such as FDDI have been conducted.

    A simulation model to analyze the performance of FDDI MAC protocol has been developed and formulated a procedure to select and tune FDDI network parameters to obtain the best possible performance under different operating conditions. An analytical model to estimate the throughput of FDDI network with synchronous and asynchronous traffic was established and the boundary condition and stability of this network was studied.

    Fault-tolerant design for dual-ring networks

    A dual-counter rotating rings such as FDDI with reconfiguration capability can enhance the network fault-tolerance. In this project, an automatic failure isolation and reconfiguration methodology (FIRM) was developed for dual counter-rotating ring networks to detect, locate, and bypass physical failures. The strategy is to significantly improve the network reliability with maximum possible connectivity and without increasing the network length. A software implementation of the FIRM algorithm have been carried out.

    For Details See the Relevant Publications

  • Y.Y. Yang and R. Sankar, An Automatic Failure Isolation and Reconfiguration Methodology for Dual-Ring Networks, IEEE Network , Vol. 7, No.5, pp. 44-53, September 1993.
  • Y. Y. Yang and R. Sankar, Analysis of Maximum Throughput for FDDI Network with Combined Synchronous and Asynchronous Traffic, Proc. Second International Conf. on Computer Communications and Networks (IC3N), San Diego, CA, June 1993, pp. 33-37.
  • R. Sankar and Y. Y. Yang, An Automatic Failure Isolation and Reconfiguration Methodology for FDDI, Proc. International Conf. on Communications (ICC '92), Chicago, IL, June 1992, pp. 186-190.
  • Y. Y. Yang and R. Sankar, Maximizing FDDI network performance by parameter tuning, Proc. Infocom '91, Miami, FL, Apr. 1991, pp. 1431-1439.
  • Y. Y. Yang, Performance Modeling and Automatic Reconfiguration Methodology for Fiber Distributed Data Interface (FDDI) Network, Ph.D. Dissertation, June 1993.
  • Y. Y. Yang, Modelling and Performance Analysis of Fiber Distributed Data Interface (FDDI), M.S. Thesis, July 1989.
  • R. Sankar and Y. Y. Yang, Fault Tolerant and High Performance FDDI Network for Space Station Application, The Florida High Technology and Industry Council, February 1991, (Final Report, 61 pages).

  • Integrated Services Support in MAN-ATM Networks

    The main objective is to support integrated services in a MAN (DQDB subnet) internetworked with ATM while satisfying the QoS requirements. An architecture is presented for the support of integrated services between two remote MAN users via ATM network. A dynamic bandwidth sharing scheme via renegotiation for applications with flexible bandwidth requirements is proposed.

    For Details See the Relevant Publications

  • K. Kidambi, R. Sankar, and J. Ottensmeyer, A QoS Mapping Scheme and a Model for MAN-ATM Inter(net)working, Computer Communications, Vol. 19, No. 3, pp. 276-286, March 1996.
  • K. Kidambi, R. Sankar, and H. Kaur, A Dynamic Bandwidth Allocation Rule for Connection-oriented DQDB-ATM and Integrated Services Support, Proc. IEEE Globecom '95, Singapore, November 1995, pp. 383-387.
  • K. Kidambi, R. Sankar, and J. Ottensmeyer, Internetworking MANs to ATM for Broadband Services Support, Proc. 20th IEEE Annual Conference on Local Computer Networks, Minneapolis, MN, October 1995, pp. 102-111.
  • K. Kidambi and R. Sankar, MAN-ATM Internetworking and Integrated Services Support, Proc. IEEE Southeastcon '95, Raleigh, NC, March 1995, pp. 1-5.
  • K. Kidambi, Bandwidth Allocation Using QoS Mapping and a Renegotiation Scheme for Integrated Services MAN-ATM Networks, Ph.D. Dissertation, May 1996.