Extending OpenFlow for SDN-enabled synchronous Ethernet networks

There is an increasing need of synchronization and clock frequency distribution in core and access networks. Synchronous Ethernet (SyncE) is a technology that is able to distribute clock frequency over Ethernet networks, while keeping scalability and reduced costs. Software-Defined Networking (SDN) is another emerging technology that is changing the landscape of network management by separating the control and data planes and introducing a centralized management architecture, with the goal of optimizing network operations. OpenFlow is currently the most popular southbound interface between the control and data planes in SDN networks. In order to operate SyncE networks under the new SDN paradigm and exploit its advantages, an extension of OpenFlow messages and operations is needed. This paper discusses how SDN and SyncE can interoperate, proposes a set of OpenFlow extensions that are backwards compatible with SyncE equipment, and presents results from a an implementation.