What is management plane in SDN?

Question

I was reading about SDN technology and its concept of a 'management plane' along with data plane and control plane.

I understand the other two, but what is management plane? Is it any kind of simple GUI interaction for operators or it is more than that?

Answer 1

The management plane contains the traffic used by the network administrator to manage the network. It can be HTTP (if you used a web UI), SSH, SNMP.

Basically the traffic is characterized like this:

• Management plane: User<->devices to configure devices (e.g., SNMP or SSH)
• Control plane: device<->device to determine actual forwarding policies (e.g., OpenFlow or BGP updates)
• Data plane: the traffic that is forwarded through the network (e.g., VoIP, HTTP sessions, etc)

NB: the management plane is sometimes considered as a subset of the control plane

Answer 2

Strictly speaking, most of SDN literature does not address the "management plane" as you have mentioned in the question. Control plane and its separation from data plane gets the bulk of the focus.

As rightly mentioned by CaptainCap above, the management plane is the interface between User (Network admin/ops to be precise) and devices. Also, it's not just limited to configuring of devices, but also monitoring the devices by gathering information from them from time to time (classic NMS function) and generating reports based on the data collected. This in turn can help network administrators identify potential problems / trends and take corrective action - in the form of short term fixes / long term solutions. This kind of monitoring / data collection is not part of control plane, and I am not sure how/if it can fit the "north bound / south bound" API model within the SDN architecture.

Check out this article, though old, does point to the same thing - https://www.sdxcentral.com/articles/contributed/does-sdn-make-my-network-management-look-fat/2012/09/