Bandwidth and Congestion Aware Routing for Wide-Area Hybrid Networks

An increasing number of science projects rely on sensors to gather data from remote areas. For example, a wildfire detection project deploys video cameras to various high-risk areas to identify wildfires as quickly as possible. These projects typically depend on hybrid networks that are composed of a combination of wireless and wired links to stream data from sensors to datacenters. The management of such hybrid networks is a burdensome task as both link capacities and traffic rates of flows are dynamic and unpredictable.In this paper, we introduce a BAndwidth- and Congestion Aware Routing (BACAR) for hybrid networks using Software Defined Networks. We use active delay measurements to identify congested links and update their capacity to measure traffic rate to detect any link capacity degradation events. We test BACAR in Mininet and show that it offers a robust solution to detect band-width fluctuations that can happen in long-distance wireless links and find alternative routes for rate-sensitive flows to improve overall network utilization and enhance flow performance.

I. Introduction

Individual edge devices and locations communicate (via wireless or wired ethernet) with a set of middle aggregation points, which are in turn connected by fiber or high-speed microwave backhaul links to form an interconnected infrastructure leading to private datacenters or cloud services as illustrated in Figure 1 . The resulting end-to-end network topology is highly variable in terms of availability and capacity over both space and time, often due to conditions outside of engineering control such as weather, radio interference, or physical disturbance.