Endpoint-transparent Multipath Transport with Software-defined Networks

Multipath forwarding consists of using multiple paths simultaneously to transport data over the network. While most such techniques require endpoint modifications, we investigate how multipath forwarding can be done inside the network, transparently to endpoint hosts. With such a network-centric approach, packet reordering becomes a critical issue as it may cause critical performance degradation. We present a Software Defined Network architecture which automatically sets up multipath forwarding, including solutions for reordering and performance improvement, 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. We implemented a prototype with commonly available technology and evaluated it in both emulated and real networks. Our results show consistent throughput improvements, thanks to the use of aggregated path capacity. We give comparisons to Multipath TCP, where we show our approach can achieve a similar performance while offering the advantage of endpoint transparency

A survey of routing protocols for energy constrained ad hoc wireless networks

In this survey we review energy-aware routing protocols for wireless multihop ad hoc networks and critically discuss the main results in this area. The classification presented is in no case unique but summarizes the chief characteristics of the many published proposals for energy conservation. A common pitfall detected in most of the studies is the lack of unambiguous notion of network's lifetime and hence of clear objective of the designed algorithm. We, therefore, define first what operational lifetime for ad hoc networks means and then analyze the achievements from that angle. After getting insight into the different energy-aware routing protocols we point out another approach for extending network's operational lifespan, which has been overlooked in the relevant literature.Peer Reviewe

The support of multipath routing in IPv6-based internet of things

The development of IPv6-based network architectures for Internet of Things (IoT) systems is a feasible approach to widen the horizon for more effective applications, but remains a challenge. Network routing needs to be effectively addressed in such environments of scarce computational and energy resources. The Internet Engineering Task Force (IETF) specified the IPv6 Routing Protocol for Low Power and Lossy Network (RPL) to provide a basic IPv6-based routing framework for IoT networks. However, the RPL design has the potential of extending its functionality to a further limit and incorporating the support of advanced routing mechanisms. These include multipath routing which has opened the doors for great improvements towards efficient energy balancing, load distribution, and even more. This paper fulfilled a need for an effective review of recent advancements in Internet of Things (IoT) networking. In particular, it presented an effective review and provided a taxonomy of the different multipath routing solutions enhancing the RPL protocol. The aim was to discover its current state and outline the importance of integrating such a mechanism into RPL to revive its potentiality to a wider range of IoT applications. This paper also discussed the latest research findings and provided some insights into plausible follow-up researches

Improving routing performance of multipath ad hoc on-demand distance vector in mobile add hoc networks.

The aim of this research is to improve routing fault tolerance in Mobile Ad hoc Networks (MANETs) by optimising mUltipath routing in a well-studied reactive and single path routing protocol known as Ad hoc On-demand Distance Vector (AODV). The research also aims to prove the effect of varying waiting time of Route Reply (RREP) procedure and utilising the concept of efficient routes on the performance of multipath extensions to AODV. Two novel multipath routing approaches are developed in this thesis as new extensions to AODV to optimise routing overhead by improving Route Discovery Process (RDP) and Route Maintenance Process (RMP) of multipath AODV. The first approach is a Iinkdisjoint multipath extension called 'Thresho)d efficient Routes in multipath AODV' (TRAODV) that optimises routing packets ~verhead by improving the RDP of AODV which is achieved by detecting the waiting time required for RREP procedure to receive a threshold number of efficient routes. The second approach is also a link-disjoint mUltipath extension called 'On-demand Route maintenance in Multipath AoDv' (ORMAD) which is an extension to TRAODV that optimises routing packets and delay overhead by improving the RMP of TRAODV. ORMAD applies the concepts of threshold waiting time and efficient routes to both phases RDP and RMP. It also applies RMP only to efficient routes which are selected in the RDP and when a route fails, it invokes a local repair procedure between upstream and downstream nodes of the broken link. This mechanism produces a set of alternative subroutes with less number of hops which enhances route efficiency and consequently minimises the routing overhead. TRAODV and ORMAD are implemented and evaluated against two existing multipath extensions to,AODV protocol and two traditional multipath protocols. The existing extensions to AODV used in the evaluation are a well-known protocol called Ad hoc On-demand Multipath Distance Vector (AOMDV) and a recent extension called Multiple Route AODV (MRAODV) protocol which is extended in this thesis to the new approach TRAODV while the traditional multipath protocols used in the evaluation are Dynamic Source Routing (DSR) and Temporally Ordered Routing Algorithm (TORA). Protocols are implemented using NS2 and evaluated under the same simulation environment in terms of four performance metrics; packet delivery fraction, average end-to-end delay, routing packets overhead, and throughput. Simulation results of TRAODV evaluation show that the average number of routes stored in a routing table of MRAODV protocol is always larger than the average number of routes in TRAODV. Simulation results show that TRAODV reduces the overall routing packets overhead compared to both extensions AOMDV and MRAODV, especially for large network size and high mobility. A vital drawback of TRAODV is that its performance is reduced compared to AOMDV and MRAODV in terms of average end-to-end delay. Additionally, TORA still outperforms TRAODV and the other extensions to AODV in terms of routing packets overhead. In order to overcome the drawbacks of TRAODV, ORMAD is developed by improving the RDP of TRAODV. The performance of ORMAD is evaluated against RREP waiting time using the idea of utilising the efficient routes in both phases RDP and RMP. Simulation results of ORMAD show that the performance is affected by varying the two RREP waiting times of both RDP and RMP in different scenarios. As shown by the simulation results, applying the short and long waiting times in both phases tends to less performance in terms of routing packets overhead while applying the moderate waiting times tends to better performance. ORMAD enhances routing packets overhead and the average end-to-end delay compared to TRAODV, especially in high mobility scenarios. ORMAD has the closest performance to TORA protocol in terms of routing packets overhead compared to ~M~a~M~OW . Relevant concepts are formalised for ORMAD approach and conducted as an analytical model in this thesis involving the\vhole process of multipath routing in AODV extensions. ORMAD analytical model describes how the two phases RDP and RMP interact with each other with regard to two performance metrics; total number of detected routes and Route Efficiency.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

AOMDV with Load Balanced as an Improvement to AOMDV Protocol

MANETs are one of the most challenging and growing research field because of their demand and challenges in providing services because of its dynamic nature. Load balancing is one of the key problems in MANETs as load balancing in network is essential for better lifetime of network, Qos, congestion control. The proposed approach in the research emphasises on the stability of the paths and distributing the traffic in the network based on the energy of the nodes. The simulations were performed in NS2. The results shows that the proposed algorithm was able to achieve batter packet delivery ratio and throughput without increasing the overhead in the network, The proposed algorithm also managed to consume a balanced energy from all the nodes in the network