ICONA: A Peer-to-Peer Approach for Software Defined Wide Area Networks Using ONOS

Several Internet Service Providers (ISP) are planning to innovate their infrastructures through a process of network softwarisation and programmability. The Software-Defined-Network (SDN) paradigm aims at improving the design, configuration, maintenance and service provisioning agility of the network through a centralised software control plane which is in charge of managing the entire system. This is easily achievable for local area networks, typical of data centres, where the benefits of having programmable access to the entire network is not restricted by latency. However, in Wide Area Networks, a centralised control plane limits the speed of responsiveness in reaction to time-constrained network events due to unavoidable latencies caused by physical distances. A logical step towards robustness in SDN is to distribute the load of the control plane between entities, each taking care of a portion of the entire geographical network and each providing an east-west communication interface to enable programmability of the entire network. Moreover, a key objective of an SDN control plane targeting an ISP networks is the east-west interface with external domains under the control of other providers. In this article we present ICONA (Inter Cluster Onos Network Application), a tool that has the objective of enabling programmable networks to span multiple clusters of controllers within either a single or multiple administrative domains. In particular, the paper describes the architecture behind ICONA and provides an initial evaluation obtained on a preliminary version of the tool, built on top of the cutting-edge network controller ONOS, Hummingbird release.