Salem Nasri

An approach for end-to-end QoS and network resources management

Abstract In this paper, we address the problem of the end-to-end QoS management for multimedia and real-time applications. We would focus on the presentation of a multi-profile communication environment and its reliability in ensuring end-to-end QoS management in the network communication processes. This communication environment, called Virtual Communication Support (VCS), provides a dynamic assignment of application requirements to the network resources reservation and protocol layers invocation. The advantage of this model is that it performs the capabilities of the network by abstracting the details of all communication stacks-layers that must be invoked in the communication process from application specificities and needs. A great attention is devoted to the end-to-end QoS management in the VCS communication model. We would present our approach for the development of a transport middleware for end-to-end QoS control. This middleware performs the QoS management with an adaptive and predictive algorithm based on the network jitter measurement. The main contribution of this paper is that it provides a solution to predict congestion during communication process and then it can avoid network overloading. This is of several importances when we are streaming multimedia real-time packets. In fact, when real-time application losses some packets it may lead to unfavorable situations. Our approach for the specification and the design of the middleware is based on the use of the Specification and Description Language (SDL). This is a formal description technique that enables model validation extension and reusability. The dynamic behavior of this model is being checked with the Message Sequence Chart (MSC). The simulation and validation of this middleware was performed for the VCS. It was simulated by The Network Simulator (NS). Some profiles with the JAVA language on the Fast-Ethernet Local Area Network. Its testing was performed for a real-time manufacturing process and multimedia supervision for control processes.

QoS and network resources management for communication in distributed manufacturing processes

In this paper, we present a multimedia communication model based on the virtual manufacturing device (VMD) concept that has been defined in the international manufacturing message specification (MMS). This model called the virtual communication support (VCS), makes it possible to cohabit different communication techniques, such as ATM and ethernet, provides a multiprofile solution to introduce real-time multimedia applications and manages network resources. Its specification and design used to perform workstation capabilities to avoid network bottleneck. For these purposes, it defines a service set between the application layer and the other communication layers to manage network resources reservation negotiate the quality of service (QoS) and ensure real-time service execution. The design of this communication model is based on the idea of the specification and description language (SDL) use. It is a formal description technique that enables model validation, extension and reusability. The dynamic behavior of this model is being checked with the message sequence chart (MSC).The implementation and the experimentation of this VCS model are being achieved using the JAVA language. It is being done on the fast-ethernet local area network equipped with multimedia and manufacturing devices.

TCP flow control technique for an interworking interface: hardware implementation

Abstract Current TCP flow control depends on packet losses to find the workload that a network can support. A variety of situations, including lossy wireless networks, asymmetric networks and web traffic workload, violates many of the assumptions made by TCP, causing degraded end-to-end performances. To improve the performance of TCP over heterogeneous networks (Ethernet and ATM interconnection), we propose a new technique, which we call Vegas–Snoop+, based on Vegas and Snoop protocols. Two modified service elements take part on the Vegas–Snoop+ technique. First, Vegas service element manages the connection parameters to achieve better throughput. Second, Snoop service element isolates the Ethernet senders from the characteristics of the ATM link. The objective in this paper is to win from advantages of Vegas and Snoop protocols, as well as to search an interconnection interface for networks interoperability. Actually, the development of two new integrated circuits (the BCM5680 (switch) and the BCM5401 (PHY)) orientate researchers to implement, at higher layer of the OSI model, flow control mechanisms to ensure reliability. Vegas–Snoop+ is an implementation of TCP, which gives in this way a solution for traffic management and congestion control improving good throughput with more reliability.

An industrial local network architecture in a Mini-MAP environment

Local industrial network performances are mainly dependent on the layer-architecture and communication protocols. The service qualities in time and reliability are severely constraint on the layer-interfacing service nature and management. The authors primary goal in this paper is to define a particular MAP (manufacturing automation protocol) architecture for a local industrial area. This architecture would reduce the cost of software development and maintenance: the Mini-MAP/EPA architecture (enhanced performance architecture). They try to describe a MMS (manufacturing message specification) Mini-MAP server behavior and its deferent service types. The description of the shop network aims to give implementation tools of the IEEE (Institute of Electrical and Electronics Engineers) 802.4 protocol in the MAC under data-link-layer and the IEEE 802.2 protocol LLC under-data-link-layer.

Peformance evaluation of fuzzy controller for traffic stabilization

This paper proposes a useful algorithm approach to hybrid control systems combining fuzzy logic and predictable control techniques for network infrastructure. The given model employs two rules to Fuzzy logic rate prevention based on queue length and buffer frequency. The learning rule for this network must then be modified accordingly. The implementation of the fuzzy model was carried out in simulation phase. The simulation was tested with several scenarios. Obtained results proved favourable comparing to ideal models.

Performance evaluation of compensation/reward mechanism for resource allocation in wireless networks

In this paper we evaluate an algorithm to distributing resources provided by the access point at the MAC layer in wireless networks. We consider a TDMA/FDD-based mechanism. System model is designed and tested for a wireless ATM networks architecture. In fact, the QoS characterising ATM technology provides the ability to well transmit multiple traffic types and treat every one according to some generic parameters. The basic idea used in this work is to provide slots reassignment, and to dynamically adjust present parameters. Simulation tests show that developed algorithms provide better results and permit to decrease blocking probability for new connections, particularly to CBR connections.

A QoS middleware for multi-protocol environment specification and design

In this paper we address the end-to-end QoS problem for multimedia and real-time applications. We focus on the presentation of a multi-profile communication environment and its reliability to ensure end-toad QoS management in the network communication processes. This communication environment called Virtual Communication Support (VCS) provides a dynamic assignment of application requirements to the network resources reservation and protocol layers invocation. The powerful of this model is that it performs the capabilities of network by abstracting the details of all communication stack -layers, that must be invoked in the communication process, from application specificitys and needs. The best attention, is given to the-end-to end QoS management in the VCS communication model. We present our approach in the development of a transport middleware for end-toad QoS control. This middleware perfoms the QoS management with an adaptive and predictive algorithm based on the network jitter management. Our approach for the specification and the design of this middleware is based on the idea of the Specification and Description Language (SDL) pattern use. For its dynamic behavior check, we have used the associated tool called MSC (Message Sequence Chart). The validation of this middleware has been realized on the VCS communication model. It has been implemented with the Java language on the Fast-Ethemet Local Area Network. Its experimentation is realized for real time manufacturing process and multimedia supervision and control processes.