There are two modern approaches to manage network devices: IETF’s NETCONF/YANG[1] and ONF’s OF-CONFIG/OpenFlow[2]. The former is much closer to current device management practices and relatively well adopted by the traditional transport network vendors. The latter changes significantly not only the architecture[3], but troubleshooting, assurance, security and other practices. It also disrupts traditional vendors’ market positions, thus meets fierce resistance from them.
It is worth mentioning that there is a migration path from NETCONF/YANG to OF-CONFIG/OpenFlow. “OF-CONFIG 1.2 requires that devices supporting OFCONFIG MUST implement the NETCONF protocol as their transport protocol.”[4] “OF-CONFIG 1.2 has a companion YANG module, also distributed as a separate file to aid in implementation of the OF-CONFIG data model. Implementers that already use the NETCONF tools could profit by using the YANG module to reduce implementation time.”[5]. This simplifies migration from NETCONF/YANG to OF-CONFIG/OpenFlow.
It is recommended to start from NETCONF/YANG adoption, then gradually introduce OF-CONFIG/OpenFlow alternatives for some use cases. This enables safer start. Since transition started, OF-CONFIG/OpenFlow should be pushed where possible, the reasons described in Phase 2.
[1] evolutionary approach to unify network device management; used mainly to replace CLI/SNMP-based management of traditional (intelligent) network devices
[2] revolutionary approach for disintegrated environments with “dumb” devices, SDN controllers and intelligent management applications on top of the controllers
[3] Intelligence of network devices (protocol stacks, policies, etc.) are to be moved to applications in or above SDN controllers.
[4] of-config-1.2.pdf
[5] of-config-1.2.pdf