ITPEC FE Morning October 2019 Question 34
Which of the following is an architecture that decouples the network control and forwarding functions, enabling the network control to become directly programmable and the underlying infrastructure to be abstracted for applications and network services?
Explanation
Software-defined networking (SDN) — it separates the control plane from the forwarding plane and makes the network programmable from a central controller.
In a conventional network every switch and router decides for itself where to send traffic. SDN moves those decisions to a controller; the devices only forward according to rules the controller installs, for example over OpenFlow. Applications program the network through the controller's interfaces without dealing with each device.
Answer (d)
Why not others:
- •(a) Cloud computing — delivering computing resources as services over a network, not a way of splitting network control from forwarding
- •(b) Internet of things — connecting sensors and everyday devices to the internet; it uses networks but defines no network architecture of this kind
- •(c) Network function virtualization — runs network functions such as firewalls and load balancers as software on general-purpose servers; it replaces dedicated appliances but does not separate control from forwarding
Key rule: SDN separates who decides (a central controller) from who forwards (the devices); NFV replaces network hardware with software on standard servers, and the two are often combined.
Networks · AI-written, may contain errors
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