B4N Controller is the key component of the Carrier Ethetnet Transport solution. It provides automated provisioning of Carrier Ethernet services – E-Line, E-Tree, E-LAN EVCs, while supporting multilayer QoS, Traffic Engineering, Path Protetion, IP Routing and L2 service OAM (Operations, Administration & Management) through CFM (Connectivity Fault Management). B4N Controller translates service policies into a set of OpenFlow rules and load this rules into the chain of switches participated in the services.
For example, for E-Line service (“point-to-point” link) B4N Controller calculates primary and backup paths, sets QoS rules, maximum and commited bandwith, etc. Administrator also could define how the prefered paths should be chosen – typically calculated paths based on bandwidth or constraint-based traffic-engineered paths.