Enhancing network robustness via shielding

Abstract

Abstract-We consider shielding critical links to guarantee network connectivity under geographical and general failure models. We develop a mixed integer linear program (MILP) to obtain the minimum cost shielding to guarantee the connectivity of a single SD pair under a general failure model, and exploit geometric properties to decompose the shielding problem under a geographical failure model. We extend our MILP formulation to guarantee the connectivity of the entire network, and use Benders decomposition to significantly reduce the running time by exploiting its partial separable structure. We also apply simulated annealing to solve larger network problems to obtain near-optimal solutions in much shorter time. Finally, we extend the algorithms to guarantee partial network connectivity, and observe significant reduction in shielding cost, especially when the failure region is small. For example, when the failure region radius is 60 miles, we observe as much as 75% reduction in shielding cost by relaxing the connectivity requirement to 95% on a major US infrastructure network.

Embedded network design to support availability differentiation

“…Furthermore, there are differences within the availability of buried cables depending on shielding, isolation and how the cable is buried (direct, microtrenching, ducted, etc.) [15]. Also, cables that traverse different terrains (metropolitan, rural, forest, etc), experience different rates of construction work and different weather conditions [24] which results in different failure rates.…”

“…However, operators are constrained by the CAPEX/OPEX allocated for modifications, operations and maintenance, leaving the methods adopted subject to their efficiency (expected gain) and cost. Here, we study the scenario where each link in a network, can be purposely strengthened so that its MTBF is increased, for example by modifying the cabling (e.g., burying an aerial cable) [26,27] or adding physical protection [15,16] or the MTTR is reduced by focused maintenance and repair efforts [26,28,29]. For each link, the possible options to increase their availability can be collected and each one will result in different levels of availability and cost.…”

“…An alternative approach to achieving high availability is to increase the availability of network components. The authors of [15,16] try to optimize network availability by improving the availability of a subset of physical links via shielding. In addition, Botton et al [17] study a network design problem with a subset of edges that for a given cost can be upgraded to be more reliable.…”

Improving Network Availability—A Design Perspective

“…Improving the availability of selected network elements (nodes and/or links) is a different approach to achieve high availability. In [15] the authors select some links to be shielded, making them resilient to failures. Given a desired end-to-end availability, several variants of a heuristic for selecting links for an availability upgrade is proposed in [16].…”

FRADIR: A Novel Framework for Disaster Resilience

“…The spine concept was first presented in [14] to denote a highly available part of the network at the physical layer. Later, in [15] the authors seek to shield (make invulnerable) a set of links to ensure connectivity of the network against certain failures. Using these network design approaches against disaster failure events could be very inefficient (e.g., an excessive number of links have to be shielded).…”