Service Specific Connection Oriented Protocol Research Articles

Improving data transport performance through SSCOP with rate-based flow control

This work tries to improve the effective throughput as well as to achieve better fairness of the transport protocol with efficient selective retransmission scheme. The commonly used transport layer protocol, transmission control protocol (TCP), has been developed for more than two decades, but its retransmission scheme is hard to be satisfactory. However, service specific connection oriented protocol (SSCOP) provides an excellent retransmission mechanism with poor flow control function. When the lower layer protocol is Asynchronous Transfer Mode, using SSCOP instead of TCP/IP over AA5 to provide transport layer service can specifically reduce the protocol overhead. We propose a scheme for SSCOP to enhance its flow control performance. This scheme combines the rate-based flow control with the queuing delay control. The simulation result shows that our enhanced SSCOP achieves both higher throughput and better fairness. It demonstrates that a proper flow control scheme with efficient selective retransmission is crucial for optimizing the performance of a transport protocol.

Satellite ATM networks: a survey

Satellite ATM networks have significant advantages over terrestrial ATM networks. Satellites provide unique advantages such as remote coverage with rapid deployment, distance insensitivity, bandwidth on demand, immunity to terrestrial disasters, and offering broadband links. Satellite ATM networks will play an important role in the rapidly evolving information infrastructure. However, there are several obstacles which need to be overcome so that satellite ATM networks can operate in full service. The objective of this survey is to present the state of the art in satellite ATM networks and to point out open research problems. We explain the satellite ATM network architecture and cover the requirements and technical barriers for seamless integration of ATM and satellite networks. We describe the feasibility of the existing ATM cell transport methods, and deal with conventional and new satellite link access methods, and some error control schemes for the satellite environment. We then describe the problems of the proposed traffic and congestion control schemes, followed by the error performance of the Transmission Control Protocol (TCP) and Service-Specific Connection-Oriented Protocol (SSCOP) for the satellite ATM network. We present basic requirements and a possible architecture for local area-metropolitan area network (LAN-MAN) interconnection using satellite ATM and then discuss the requirements for multimedia services in satellite ATM networks.

Network-based parallel computing over ATM using improved SSCOP protocol

In this paper, we address the problem of supporting network-based parallel computing, usually known in the literature as High Performance Distributed Computing (HPDC), over ATM networks. For this purpose, we consider a logically separate subnetwork for HPDC applications. After presenting an architectural reference model for the HPDC subnetwork and distinguishing which functions should be installed over the ATM network in order to satisfy the needs of HPDC applications, we suggest two different modifications of the loss recovery mechanism of the Service-Specific Connection Oriented Protocol (SSCOP) that aim at optimizing communications by taking advantage of both the special properties of HPDC traffic and the cell-based nature of ATM. The performance of these mechanisms is evaluated and compared with that achieved by the standard mechanism of the SSCOP protocol. The results show that, when the ATM network experiences high load and the HPDC applications make an intensive use of arrays, SSCOP including the new retransmission mechanisms becomes more robust than standard SSCOP, and provides low latency and efficient cell loss recovery. From the results, we conclude that the introduction of cell-based retransmission mechanisms does contribute to enhance the performance of ATM network-based parallel computing.