- [Instructor] SDN implementations have northbound
and southbound APIs.
So what is actually a northbound and a southbound API?
Basically, in an SDN architecture,
a southbound API is used to communicate
between the SDN controller
and the switches or routers within the infrastructures.
These APIs can be open or preparatory.
Cisco proxy provides detailed information
about all the APIs that are supported in different platforms
in the DevNet website or developer.cisco.com.
I highly suggest for you to become familiar
with this website, and not only that,
but they actually provide a lot of different exercises
and you know,
study material that you can actually use
for free from Cisco.
And later throughout the course,
you're gonna learn about using different APIs to
you know, perform different functions
in networking devices as well.
Now, south bound APIs enable the SDN controller
to dynamically make changes based on real time demands,
and also based on scalability needs, right?
Now, the OpenFlow and the Cisco OpFlex
are examples that actually provide,
or examples of implementations that provide
southbound API capabilities.
Now, northbound APIs, or SDN northbound APIs,
are typically restful APIs that are used to communicate
between the SDN controller
and the services and applications running over the network.
So, these northbound APIs can actually be used
for the orchestration and the automation
of the network components to align with the different needs
of applications via SDN network programmability.
So in short,
northbound APIs actually are basically the link
between the application and the SDN controller.
In modern environments,
applications actually can tell the networking devices
whether it's a physical, you know,
a system or a virtual network device or appliance.
What are the types of resources that actually they need?
And in turn, the SDN solution can actually provide
the necessary resources to that application.
Now, Cisco has a concept called the intent-based networking,
and in many different locations
you may see northbound APIs referred
to as intent based APIs.