The proliferation of different types of device interfaces places a significant burden on application developers and equipment providers alike. One of the reasons for the rise of Software Defined Networking (SDN) is its promise to simplify management by providing a single point through which the entire network can be managed and administered. This raises the question whether this promise extends towards dramatic simplification of the device interface landscape as well, specifically, whether SDN can put an end to device interface proliferation and in the future a single management and control interface may be all that is required. Unfortunately, it turns out that this particular hope is unsubstantiated. Here is why.
The Promised SDN Land of Interface Simplification
Much has been made of the need to align the various interfaces through which networking devices can be managed and controlled. It has been difficult enough to just keep SNMP implementations consistent. Throw CLI, syslog, and Web Services into the mix, and the task becomes daunting indeed. One reason why different interfaces have to be supported has to do with customer preferences, of course. Chef is the new paradigm to support? Sure, we’ll add that. ReST is becoming en-vogue? We’ll support that too.
In the middle of all this, along comes SDN. “Don’t bother with individual devices and their legacy interfaces” is the siren call. “Use a controller to orchestrate the network instead” – a single point of control through which the network can be operated and maintained, an enticing value proposition indeed. Early SDN technology such as OpenFlow made a big splash and gained a lot of mind share this way. Rather than messing with the hodgepodge of existing interfaces, a single interface was introduced to control OpenFlow switches. Just support this one interface, or so the message went, and your equipment can join the New World of Software-Defined Networking, leaving the Old World of fragmented interfaces behind, much like early European settlers coming to America hoped for freedom and a better life, leaving behind constantly quarreling fiefdoms and many centuries of historical baggage. Read More »