What is the etymology of 'plane' e.g. data plane, control plane, etc.?

Question

My guess would be aviation (used as an analogy), but I find no source for this.

Data plane was being used as early as 1965 (e.g. in this paper) https://ieeexplore.ieee.org/abstract/document/4038491 "the planes prepared by the factory must anticipate all possible situations." This suggests the plane is something physical?

(I guess what I was really wondering is how the term has evolved from electronics cases (a physical plane of wires), through telecoms (originally physical planes), then to networking, then to nowadays we talk about a 'control plane' in Kubernetes - is this derived from the original use case in the 1965 paper?)

Answer 1

Welcome to EE.SE.

As the other answers have noted, plane means a flat surface.

Your 1965 reference is discussing magnetic core memory. This consists of small magnetic ferrite rings woven into a flat surface:

Source: Wikipedia

So your 1965 paper is discussing these physical memory planes. They are inherently two-dimensional as they use X and Y wires to address each ring, visible as the horizontal and vertical wires in the above picture. A diagonal sense wire reads the state of the addressed ring.

A practical computer would have many of these planes stacked together, as discussed on Ken Shirriff's blog. (An excellent resource for computing history.)

In modern computer networking terminology data plane, control plane (and management plane) are used as abstractions to define conceptual levels within networking devices:

Source: www.researchgate.net figure 1

The physical implementation may reflect the abstract separation, with separate physical circuitry to implement the different planes, or the separation may be purely abstract, with one physical processor running software to perform the functions of each plane.

Answer 2

A "plane" is a flat thing, a surface.

The use of "plane" in memory is pretty literal; in a bus it's a collection of parallel lines, ie, a surface or plane; in a network it's a slice through the high-dimension space of the network.

Updated question:

nowadays we talk about a 'control plane' in Kubernetes - is this derived from the original use case

My reading of the definitive Exford English Dictionary article would say it's this figurative meaning:

plane n3 6. figurative. A level, degree, or standard of awareness, thought, performance, attainment, etc.; (Theosophy) each of a number of interpenetrating levels of existence of which the universe is believed to be constituted, and through which it is believed to be slowly evolving.

It gives examples such as "the mental plane, the physical plane, the metaphysical plane".

Which is exactly what we have in the general sense of control plane, data plane etc.

The OED gives this origin in English from the 1600s.

Etymology: < classical Latin plānum flat or level ground, (in geometry) a plane figure, use as noun of neuter singular of plānus plain adj.²

And says this about core memory:

plane n3 8. Computing. Any of the flat, usually square arrays of magnetic cores or other elements in a memory, each of which contains the corresponding bits of all the words held in the arrays.

---

Digression about "aeroplane" The word "aeroplane" didn't come until the 1850s, via French, and thence by contraction to "plane". I believe it's unrelated to the use you're asking about.

Etymology: < aero- comb. form + plane n.³, partly after French aéroplane (J. Pline 1855, as both adjective and noun, referring to a proposed system of aerial navigation using an airship with a more or less horizontal surface as opposed to the then usual spherical or cylindrical shapes of balloons and aircraft (and also designating an airship of this type) [...] it has been alternatively suggested that the second element is Hellenistic Greek πλάνος wandering [...] However, this is unlikely, in view of [...]

Answer 3

It comes from latin, meaning flat surface.