System Support for Bandwidth Management and Content Adaptation in Internet Applications

This paper describes the implementation and evaluation of an operating system module, the Congestion Manager (CM), which provides integrated network flow management and exports a convenient programming interface that allows applications to be notified of, and adapt to, changing network conditions. We describe the API by which applications interface with the CM, and the architectural considerations that factored into the design. To evaluate the architecture and API, we describe our implementations of TCP; a streaming layered audio/video application; and an interactive audio application using the CM, and show that they achieve adaptive behavior without incurring much end-system overhead. All flows including TCP benefit from the sharing of congestion information, and applications are able to incorporate new functionality such as congestion control and adaptive behavior.Comment: 14 pages, appeared in OSDI 200

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

Network emulation focusing on QoS-Oriented satellite communication

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

Enhancing IT investments productivity: Integrating network QOS and it indirect costs

Increasing productivity is considered one of the major driving factors for a successful business. From an Information Technology (IT) infrastructure perspective, obtaining an optimised performance of resources is expected to improve productivity. From a technical viewpoint, the introduction of Quality of Service (QoS) models have been perceived to optimise the performance of the organisation network backbone. These models aim to provide an acceptable level of service assurance to the newly introduced applications and services such as voice and video. From a management viewpoint, the proper management of IT investments indirect costs can lead to a reduction of the overall cost portfolio. Consequently, both benefits and productivity increase are likely to be realised. This paper introduces network QoS strategy within the hierarchy of business infrastructure. In addition, it aims to identify the relationship between network QoS and IT indirect costs. Such integration demonstrates how network QoS strategy can be used to control IT indirect costs as well as enhancing network performance