GTFRC, a TCP friendly QoS-aware rate control for diffserv assured service

This study addresses the end-to-end congestion control support over the DiffServ Assured Forwarding (AF) class. The resulting Assured Service (AS) provides a minimum level of throughput guarantee. In this context, this article describes a new end-to-end mechanism for continuous transfer based on TCP-Friendly Rate Control (TFRC). The proposed approach modifies TFRC to take into account the QoS negotiated. This mechanism, named gTFRC, is able to reach the minimum throughput guarantee whatever the flow’s RTT and target rate. Simulation measurements and implementation over a real QoS testbed demonstrate the efficiency of this mechanism either in over-provisioned or exactly-provisioned network. In addition, we show that the gTFRC mechanism can be used in the same DiffServ/AF class with TCP or TFRC flows

Implementation and performance analysis of a QoS-aware TFRC mechanism

This paper deals with the improvement of transport protocol behaviour over the DiffServ Assured Forwarding (AF)class. The Assured Service (AS) provides a minimum throughput guarantee that classical congestion control mechanisms, like window-based in TCP or equation-based in TCP-Friendly Rate Control (TFRC), are not able to use efficiently. In response, this paper proposes a performance analysis of a QoS aware congestion control mechanism, named gTFRC, which improves the delivery of continuous streams. The gTFRC (guaranteed TFRC) mechanism has been integrated into an Enhanced Transport Protocol (ETP) that allows protocol mechanisms to be dynamically managed and controlled. After comparing a ns-2 simulation and our implementation of the basic TFRC mechanism, we show that ETP/gTFRC extension is able to reach a minimum throughput guarantee whatever the flow’s RTT and target rate (TR) and the network provisioning conditions

Network emulation focusing on QoS-Oriented satellite communication

This chapter proposes network emulation basics and a complete case study of QoS-oriented Satellite Communication

QoS-aware architecture for FHMIP micromobility

Wireless networks will certainly run applications with strict QoS requirements and so, micro-mobility protocols such as fast hierarchical mobile IPv6 (FHMIP) are useful tools to accomplish this new feature. The FHMIP is an effective scheme to reduce Mobile IPv6 handover disruption, however it does not support application's QoS requirements. Therefore, in order to provide QoS guarantees for real-time applications it is necessary to develop new traffic management schemes; this implies the optimization of network mobility support and also some network congestion control. A traffic management scheme of this type should take into account the QoS requirements of handover users and should implement a resource management (RM) scheme in order to achieve this. In this paper, a new RM scheme for the DiffServ QoS model is proposed. This new scheme is implemented by access routers as an extension to FHMIP micromobility protocol. In order to prevent QoS degradation of the existing traffic, access routers should evaluate the impact of admitting a new mobile node (MN), previously to the handover. This evaluation and sequent decision on wether admitting or refusing MN's traffic is based on a measurement-based admission control (MBAC) algorithm. This architecture, that has been implemented and tested using ns-2, includes a simple signaling protocol, a traffic descriptor and exhibits an adaptive behavior to traffic QoS requirements. All the necessary measurements are aggregated by class-of-service, thus avoiding maintaining state on the individual flows.(undefined

gTFRC: a QoS-aware congestion control algorithm

This study addresses the end-to-end congestion control support over the DiffServ Assured Forwarding (AF) class. The resulting Assured Service (AS) provides a minimum level of throughput guarantee. In this context, this paper describes a new end-to-end mechanism for continuous transfer based on TCP-Friendly Rate Control (TFRC) originally proposed in [11]. The proposed approach modifies TFRC to take into account the QoS negotiated. This mechanism, named gTFRC, is able to reach the minimum throughput guarantee whatever the flow's RTT and target rate. Simulation measurements show the efficiency of this mechanism either in over-provisioned or exactly-provisioned network. In addition, we show that the gTFRC mechanism can be used in the same DiffServ/AF class with TCP or TFRC flows

A QoS-enable solution for mobile environments

This paper addresses the problem of designing a suitable Quality of Service (QoS) solution for mobile environments. The proposed solution deploys a dynamic QoS provisioning scheme able to deal with service protection during node mobility within a local domain, presenting extensions to deal with global mobility. The dynamic QoS provisioning encompasses a QoS architecture that uses explicit and implicit setup mechanisms to request resources from the network for the purpose of supporting control plane functions and optimizing resource allocation. Abstract--- For efficient resource allocation, the resource and mobility management schemes have been coupled resulting in a QoS/Mobility aware network architecture able to react proactively to mobility events. Both management schemes have been optimized to work together, in order to support seamless handovers for mobile users running real-time applications. Abstract--- The analysis of performance improvement and the model parametrization of the proposed solution have been evaluated using simulation. Simulation results show that the solution avoids network congestion and also the starvation of less priority DiffServ classes. Moreover, the results also show that bandwidth utilization for priority classes is levered and that the QoS offered to Mobile Node's (MN's) applications, within each DiffServ class, is maintained in spite of MN mobility. Abstract--- The proposed model is simple, easy to implement and takes into account the mobile Internet requirements. Simulation results show that this new methodology is effective and able to provide QoS services adapted to application requests