eTDP: Enhanced Topology Discovery Protocol for Software-Defined Networks

Abstract

Discovering network elements in a dynamic and optimized manner and being able to contend with ever-growing traffic is a key requirement for current networking environments. In software-defined networks (SDNs), the controller collects the topology information from the data plane and maintains an abstract view of the entire network, which is crucial for the proper functioning of applications and network services. However, there is still the need for an enhanced protocol for automatic discovery and mechanisms of autoconfiguration of network elements according to new policies and business requirements. To overcome this challenge, this paper presents a novel protocol that, unlike existing approaches, enables a distributed layer-2 discovery without the need for previous network configurations or controller knowledge of the network. By using this mechanism, the SDN controller can discover the network view without incurring scalability issues, while taking advantage of the shortest control paths toward each switch. The obtained results show that our enhanced protocol is efficient in terms of time and message load over a wide range of generated networks and outperforms the state-of-the-art techniques. INDEX TERMS Network management, protocols, software-defined networks, topology discovery. CRISTINA CERVELLÓ-PASTOR received the M.Sc. and Ph.D. degrees in telecommunication engineering from the Barcelona School of Telecommunications Engineering, Politècnica de Catalunya, Barcelona, Spain, where she is currently an Associate Professor and the Head of the Department of Network Engineering. Being part of the BAMPLA Research Group, she is responsible and actively participated in diverse national and European competitive projects (NOVI, FEDER-ICA, ATDMA, A@DAN, Euro-NGI, Euro-FGI, and EURONF) and private funding research and development projects. She has published diverse papers in national and international journals and conferences. She is supervising dissertation in the field of management, optimal resource allocation, topology discovery, and routing in software-defined networks/NFV and 5G.

HDDP: Hybrid Domain Discovery Protocol for Heterogeneous Devices in SDN

“…3b and Fig. 3c represent the usual exchange of HDDP Request and HDDP Reply messages, respectively, as explained in the previous section (steps [1][2][3][4][5][6][7][8]. In the hypothetical situation in which, for example, node E3 moves, this is noticed by the periodic exchange of Hello messages.…”

“…However, OFDP requires that all devices support OpenFlow [3]. Diverse protocols including OFDPv2 [4], Tree Exploration Discovery Protocol (TEDP) [5] or enhanced Topology Discovery Protocol (eTDP) [6] outperform OFDP in terms of scalability and efficiency, however, none of them is capable of discovering non-SDN devices. The first work to tackle the discovery of resources in hybrid networks was [7], which combined LLDP with Broadcast Domain Discovery Protocol (BDDP) to unveil legacy switches located between SDN switches.…”

Comparison of Routing Algorithms With Static and Dynamic Link Cost in Software Defined Networking (SDN)

“…Local controllers respond faster and provide data-path services for the requests that need only local network state information. They redirect only the requests that require the global network view to the centralized controller [42]. This approach reduces overload on the centralized controller; but it still has the single failure of point problem [43].…”

Lagrangian-Relaxation-Based Self-Repairing Mechanism for Wi-Fi Networks

“…A self-repairing function, which is executed with software-defined networks (SDNs) [1], [2], is adopted for Wi-Fi networks. The function employs a self-configuration mechanism to adjust network parameters, such as signal strength, channel allocation, signal-to-interference-plusnoise ratio (SINR), and handover threshold, to repair network failure, to recover interrupted networks, and to avoid network service interruption [3].…”

“…Software-defined network (SDN) is a type of network framework, which allows network administrator to re-build network structure without modifying hardware equipment or to dynamically configuring the network devices by software implementation methods [3]. The next generation wireless networks (including Wi-Fi) support SDN with self-repairing function, a novel technique to ensure reliability, and a new set of networks to achieve high quality of service (QoS).…”