Controller Placement and Availability Link Upgrade Problem in SDN Networks

Abstract

In SDN networks, the problem of how many controllers and where to place them, has been extensively studied. This is known as the controller placement problem, and has been addressed mainly considering the delays between the SDN switches and controllers. Although the delays between switches and controllers and the intercontroller delays are key aspects, a less addressed issue is the availability of the control paths (the routing paths between the switches and their controllers). In this paper, * This work was partially supported by Fundação para a Ciência e a Tecnologia (FCT) under project grant UID/Multi/00308/2019 and was financially supported by ERDF Funds and National Funds through FCT under project CENTRO-01-0145-FEDER-029312.

Software-Defined Network Design driven by Availability Requirements

“…Note that this proposition is a generalization of Proposition 2 in [15], where more than one level of availability upgrade is considered. Also the definition of the aggregated decision variables x sk ij with k = 0, ..., κ, allow for a more compact linearized expression when compared to the decision variables used in [15].…”

“…• constraints (15) guarantee that if node i is distanced at most D sc from s and manages s, then a controller must be hosted in i;…”

“…In this work, we assume that the spine is a spanning tree, and that its links can be upgraded to have increased availability at a given cost [2], by reducing the average time to repair of the link -and/or reducing the time between failures (by installing more robust equipment on the link, for example). Our previous work [15] also addresses the problem of controller placement and link upgrade. However, path redundancy was not considered and the upgraded links did not have to be on a spanning tree subgraph.…”

Kernel Search-Framework for Dynamic Controller Placement in Software-Defined Network

“…Researchers in [19] consider the quality of services (QoS) in terms of latency and access control paths as a criterion in determining the controller's appropriate location. A set of connections has been selected to ensure network availability, and an exact method is used along with a heuristic method.…”

Joint optimization of primary and backup controller placement and availability link upgrade in SDN networks

“…Our previous works [17] and [18], have also addressed the CPP problem in the context of availability link upgrade. In [17], we considered maximum delay and availability guarantees for the paths connecting each switch to its controller (control paths). Path redundancy was not considered.…”