SDN Controller Programming Guide

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1 Introduction
This document describes the process of developing applications to run on the HP VAN SDN
Controller platform.
The base SDN Controller Appliance will serve as a delivery vehicle for SDN solutions. It aims to
provide a platform for developing various flavours of network controllers, e.g. data-centre, public
cloud, private cloud, campus edge networks, etc. This includes being an open platform for
development of experimental and special-purpose network control protocols using a built-in
OpenFlow controller.
The SDN Controller Appliance will meet certain minimum scalability requirements and it will
provide ability to achieve higher scaling and high-availability requirements via a scale-out teaming
model. In this model, the same set of policies will be applied to a region of network infrastructure
by a team of such appliances, which will coordinate and divide their control responsibilities into
separate partitions of the control domain for scaling, load-balancing and fail-over purposes.
Overview
Regardless of the specific personality of the controller, the software stack will consist of two major
tiers. The upper Administrator tier will host functionality related to policy deployment,
management, personae interactions and external application interactions, for example slow-path,
deliberating operations. The lower Controller tier, on the other hand, will host policy enforcement,
sensing, device interactions, flow interactions, for example fast-path, reflex, muscle-memory like
operations. The interface(s) between the two tiers provide a design firewall and are elastic in that
they can change along with the personality of the overall controller appliance. Also, they are
governed by a rule that no enforcement-related synchronous interaction will cross from the
Controller to Administrator tier.