Control Plane and Data Plane Issues in Network Layer Multipathing

Path redundancy at network layer is necessary in communication networks to ensure high network efficiency and fault tolerance. Single path routing may cause route oscillations in addition to becoming a throughput bottleneck. In order to ensure link reliability and prevention from routing oscillations, the availability of multiple paths becomes an absolute necessity. However, the design issues related to multipathing need to be resolved first for optimum network performance, especially for future networks with separated control and data planes. In this work, we outline the control plane and data plane issues associated with network layer multipathing in light of existing literature. We explore two control plane problems pertaining to route calculation and routing metric selection with regards to multipathing and gauge the options at hand. Furthermore, we expatiate three data plane multipathing issues encompassing load balancing, path quantification and their concurrent/backup usage for wired as well as wireless scenarios.