Efficient Topology Discovery Research Articles

An Efficient Topology Discovery Protocol with Node ID Assignment Based on Layered Model for Underwater Acoustic Networks.

Underwater acoustic networks are widely used in survey missions and environmental monitoring. When an underwater acoustic network (UAN) is deployed in a marine region or two UANs merge, each node hardly knows the entire network and may not have a unique node ID. Therefore, a network topology discovery protocol that can complete node discovery, link discovery, and node ID assignment are necessary and important. Considering the limited node energy and long propagation delay in UANs, it is challenging to obtain the network topology with reduced overheads and a short delay in this initial network state. In this paper, an efficient topology discovery protocol (ETDP) is proposed to achieve adaptive node ID assignment and topology discovery simultaneously. To avoiding packet collision in this initial network state, ETDP controls the transmission of topology discovery (TD) packets, based on a local timer, and divides the network into different layers to make nodes transmit TD packets orderly. Exploiting the received TD packets, each node could obtain the network topology and assign its node ID independently. Simulation results show that ETDP completes network topology discovery for all nodes in the network with significantly reduced energy consumption and short delay; meanwhile, it assigns the shortest unique IDs to all nodes with reduced overheads.

TEDP: An Enhanced Topology Discovery Service for Software-Defined Networking

Currently, software-defined networking (SDN) platforms leverage the link-layer discovery protocol (LLDP) to discover the underlying topology. However, the LLDP is suboptimal in terms of message load. In this letter, we present the tree exploration discovery protocol (TEDP), proving that shortest paths can be built at the same time that the topology information is gathered, without extra messages compared with LLDP. We also analyze two alternative implementations for the TEDP and give insights into some features that SDN platforms should ideally provide for an efficient topology discovery service.

Efficient topology discovery algorithm for software‐defined networks

Software-defined networking (SDN) already has an established presence in the networking industry as an emerging paradigm for designing network architectures, decoupling the control from the forwarding plane and offering a centralised way of network management. Cloud and enterprise infrastructure engineers have already adopted such techniques for building up their environments, deliberating the cost and flexibility advantages gained from this technology. However, smaller companies may choose a progressive replacement of their equipment due to operational and budget constraints. Hence, mixing equipment could lead up to hybrid SDN environments making network management even more complex. In this study, an event-based generic topology discovery algorithm, capable of providing an efficient packet discovery mechanism using existing protocols in SDN networks, is proposed. For testing and evaluation purposes, address resolution protocol and link layer discovery protocol are being used to extract the information needed and reconstruct the topology to the controller. Implementation is accomplished using Internet Engineering Task Force's ForCES framework.

Efficient topology discovery in OpenFlow-based Software Defined Networks

Software Defined Networking (SDN) is a new networking paradigm, with a great potential to increase network efficiency, ease the complexity of network control and management, and accelerate the rate of technology innovation. One of the core concepts of SDN is the separation of the network’s control and data plane. The intelligence and the control of the network operation and management, such as routing, are removed from the forwarding elements (switches) and are concentrated in a logically centralised component, i.e. the SDN controller. In order for the controller to configure and manage the network, it needs to have up-to-date information about the state of the network, in particular its topology. Consequently, topology discovery is a critical component of any Software Defined Network architecture. In this paper, we evaluate the efficiency of the de facto standard approach to topology discovery currently implemented by the major SDN controller frameworks, and propose simple and practical modifications, which achieve a significantly improved efficiency and reduced control overhead. We have implemented our new topology discovery approach on the widely used POX controller platform, and have evaluated it for a range of network topologies via experiments using the Mininet network emulator as well as a specific topology in the OFELIA SDN testbed. Our results show that our proposed modifications achieve an up to 40% reduction in controller load compared to the current state-of-the-art approach, while delivering identical discovery functionality.