On Bootstrapping In-Band Control Channels in Software Defined Networks

Software Defined Networking (SDN) is a rapidly emerging technology in the commercial market, and is a technology that should be embraced by the defence and emergency services to enable more flexible and adaptable communication networks in the future. Common deployment of SDN, especially in data centres, involves building a separate network for the control channel between forwarding devices and the SDN controllers. For geographically distributed networks typically found in defence and emergency services, it is often not feasible to establish a separate dedicated network for the control channel. In such networks, traffic between SDN controllers and forwarding devices therefore needs to be in-band in the same network that the SDN controllers should control. This paper describes the steps necessary for forwarding devices to both discover and set up the connections with SDN controllers when in-band control channels must be used. The work expands on earlier published work on setting up in-band control channels between SDN controllers and the forwarding devices. Especially, our solution that uses the "Intent frameworks" of major SDN controllers improves on network resilience in disconnected, intermittent and limited networks and the solution will allow for implementation of enhanced security mechanisms compared to previous work.