Abstract: Multipath forwarding consists in using multiple paths simultaneously to transport data. While most techniques in this area require endpoint modifications, this article proposes to do it inside the network, transparently to the hosts. This approach, however, is known to introduce packet reordering at the receiving end, which may cause critical performance degradation. We present a Software Defined Network architecture which automatically sets up multipath forwarding including solutions to those issues, both at the sending side, through multipath scheduling algorithms, and the receiver side, by resequencing out-of-order packets in a dedicated in-network buffer. A prototype of the model is implemented with wide-spread technologies and evaluated in both emulated and real networks. In this demo, we will show how our solution improves Quality of Experience for high quality video streaming while remaining reactive to network congestion.
Abstract: In the context of a reconfigurable transport protocol, this paper introduces two protocol instances based on the composition and specialisation of the TFRC congestion control and Selective Acknowledgment mechanisms. The two resulting transport architectures lead respectively to the QTPAF protocol, specifically designed to operate over QoS-enabled networks and the QTPlight protocol, specifically designed for resource-limited end systems connected to powerful servers. QTPAF combines QoS-aware TFRC congestion control with full reliability to provide a transport service similar to TCP but additionally taking into account network-level bandwidth reservations. QTPlight proposes a modification of TFRC that shifts from the receiver to the sender the complexity of the loss rate estimation mechanism. This modification allows to alleviate the processing and communication load of “light” resource limited mobile receivers. We present the concept of these protocols and their adaptation in the EuQoS European project framework.
Abstract: The design and development process of communication protocols and real-time systems and particularly transport protocol mechanisms requires adequate methodology and efficient instrumental support. In this paper, an extensible and QoS-oriented development framework integrating design and simulation with UML (Unified Modeling Language), and implementation and evaluation with emulation is introduced. An early use of the proposed framework is illustrated with the design and development of simple transport mechanism.