Reference Guide

Table Of Contents
The approach aims to achieve connectivity in a controlled manner and without creating undue
dependencies on specifics of component implementations. The separate tiers are expected to
interact over well-defined mutual interfaces, with decreasing coarseness from top to bottom. This
means that on the way down, high-level policy communicated as part of the deployment
interaction over the external APIs is broken down by the upper tier into something similar to a
specific plan, which gets in turn communicated over the inter-tier API to the lower controller tier.
The controller then turns this plan into detailed instructions which are either pre-emptively
disseminated to the network infrastructure or are used to prime the RADIUS or OpenFlow [11] [12 ]
controllers so that they are able to answer future switch (other network infrastructure device)
queries.
Similarly, on the way up, the various data sensed by the controller from the network infrastructure,
regarding its state, health and performance, gets aggregated at administrator tier. Only the
administrator tier interfaces with the user or other external applications. Conversely, only the
controller tier interfaces with the network infrastructure devices and other supporting controller
entities, such as RADIUS, OpenFlow [11] [12], MSM controller software, and so on.
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