Lightweight tag-based forwarding among competing gateways in Wireless Mesh Networks

Abstract

Wireless Mesh Networks have been traditionally deployed to offer Internet access. Following the general trend of convergence, they must increasingly provide customers with communication services whose quality constraints are heterogeneous. For large scale deployments, access to the Internet is provided by multiple gateways installed at different points in the network. Each gateway may be connected to the Internet with different technologies (ADSL, Ethernet, satellite, HF link) offering several alternatives to get out of the network with heterogeneous and dynamic performances. Routing QoS-constrained flows so that they always benefit from the best quality available is a challenging task. In addition to an intelligent gateway selection, it requires a forwarding system able to dynamically balance each flow towards the most suitable gateway. Existing candidates generate unnecessary complexity and overhead. In this paper, we propose a distributed and lightweight tag-based forwarding scheme that brings the flexibility required to work at the flow level, and supports dynamic traffic balancing among gateways with various bandwidth, delay or jitter characteristics. We implemented our forwarding scheme on an experimental testbed and applied it to the enforcement of simple gateway selection strategies. Results demonstrate the interest of our approach and its efficiency to dynamically forward specific flows among competing gateways.