A Pragmatic View of MANET Performance Evaluation and Design of a Prototype MAC Level Routing Algorithm

Our goal in this research is to investigate and determine how to best support a challenging mobile wireless network based in a military operational environment. Since routing protocols used in mobile ad hoc networks (MANET) must adapt to frequent or continual changes of topology, while simultaneously limiting the impact of tracking these changes on wireless resources, we focused our initial research on improving the efficiency of route discovery. We proposed and designed a new MAC layer routing protocol that pursues reduced routing overhead, greater interaction of network protocol layers and passive neighbor/path discovery. This algorithm, called Virtual MAC Tag Switching (VMTS), evolved as we implemented a prototype in the ns-2 network simulator and conducted simulation analysis of existing protocols: DSDV, DSR and AODV. Upon analyzing the performance of existing routing protocols using pragmatic metrics not applied in any MANET literature it was found that current MANET models produce unsatisfactory performance. Subsequent analysis of transport layer protocol behaviors pinpointed the causes that undermine the performance of the existing protocols and would have thwarted VMTS as well

Discovering the network topology: an efficient approach for SDN

Network topology is a physical description of the overall resources in the network. Collecting this information using efficient mechanisms becomes a critical task for important network functions such as routing, network management, quality of service (QoS), among many others. Recent technologies like Software-Defined Networks (SDN) have emerged as promising approaches for managing the next generation networks. In order to ensure a proficient topology discovery service in SDN, we propose a simple agents-based mechanism. This mechanism improves the overall efficiency of the topology discovery process. In this paper, an algorithm for a novel Topology Discovery Protocol (SD-TDP) is described. This protocol will be implemented in each switch through a software agent. Thus, this approach will provide a distributed solution to solve the problem of network topology discovery in a more simple and efficient way.Peer ReviewedPostprint (published version

Enhanced Resource Discovery Mechanisms for Unstructured Peer-to-Peer Network Environments

This study explores novel methods for resource discovery in unstructured peerto-peer (P2P) networks. The objective of this study is to develop a lightweight resource discovery mechanism suitable to be used in unstructured P2P networks. Resource discovery techniques are examined and implemented in a simulator with high scalability in order to imitate real-life P2P environments. Simulated topology generator models are reviewed and compared, the most suitable topology generator model is then chosen to test the novel resource discovery techniques. Resource discovery techniques in unstructured P2P networks usually rely on forwarding as many query messages as possible onto the network. Even though this approach was able to return many resources, the flooding of the network with query messages have an adverse effect on the network. Flooding the network has undesirable consequences such as degenerative performance of the network, waste of network resources, and network downtime. This study has developed alpha multipliers, a method of controlling query message forwarding to deal with the flooding effect of most resource discovery techniques in unstructured P2P networks. The combination of alpha multipliers and breadth-first search (BFS), ↵-BFS, was able to avoid the flooding effect that usually occurs with BFS. The ↵-BFS technique also increases the combined query efficiency compared to the original BFS. Aside from improving a uninformed search technique such as the BFS, this study also examines the network communication cost of several informed resource discovery techniques. Several issues that arise in informed resource discovery techniques, such as false positive errors, and high network communication costs for queries to update search results are discussed. This detailed analysis forms the basis of a lightweight resource discovery mechanism (LBRDM) that reduces the network communication cost by reducing the number of backward updates inside the network when utilising the blackboard resource discovery mechanism (BRDM). Simulations of BRDM and LBRDM show that the lightweight version can also return an almost identical combined query efficiency than the BRDM. The solution to control query message forwarding in ↵-BFS, and the removal of unnecessary exchange of information in LBRDM open a new perspective on simplifying resource discovery techniques. These approaches can be implemented on other techniques to improve the performance of resource discovery