This document discusses software-defined networking (SDN) and the role of APIs in SDN. It describes how SDN uses APIs to break down physical boundaries and allow all aspects of a network to be defined through software. It outlines the key elements of SDNs, including controllers that communicate with switches via APIs. Northbound APIs allow new features to be programmed into controllers. The document argues that a common northbound API across controllers could help advance SDNs and provide a single view of the software-defined network.

1. SDN and APIs
Networking Innovation Through Software
Sam Ramji @sramji
Brian Pagano @brianpagano

2. groups.google.com/group/api-craft

3. youtube.com/apigee

4. slideshare.net/apigee

5. SOFTWARE-DEFINED
NETWORKING:
Defined

6. Software-Defined Networking (SDN)
is a shift in network-based computing
based on breaking existing physical
boundaries on switches, routers, and
controllers through well-defined APIs.

7. This makes it possible to dynamically
define all aspects of a network through
software.

8. A BRIEF OVERVIEW
OF SDN

9. Originally networking was a difficult manual
process.

11. In a pre-OpenFlow network, all routing and
control work was done by a single proprietary
product.
All features were shipped by the vendor.

12. packets Router/Switch packets
Feature Feature Feature Policy-based routing
Examples
Operating System JunOS, Cisco IOS
Packet Forwarding Hardware Broadcom, Marvell

13. In an OpenFlow network, routing and control
work can be done by software running
anywhere in the datacenter. SDN controllers
drive these changes into the switching layers.

14. SDN Controller
OpenFlow API
OpenFlow Switch OpenFlow Switch OpenFlow Switch

15. It can be helpful to think of the SDN as being
made up of elements, controllers, and apps.

16. App A App B App C App D
SDN Controller
OpenFlow Switch OpenFlow Switch OpenFlow Switch

17. App A
apps
App B App C App D
controllers
SDN Controller
OpenFlow Switch
elements
OpenFlow Switch OpenFlow Switch

18. The element is where the packet processing
happens and must run at line rate.

19. packets OpenFlow Switch packets
OpenFlow API
Flow Table Flow Table Flow Table

20. Controllers have built-in features and talk to
switches via the OpenFlow API. They also
have APIs to enable new features that run
outside the controller.

21. SDN Controller
Northbound API
Feature Feature Feature
Operating System

22. These are called “Northbound APIs” and
enable programmability.

23. SDN Controller
Northbound API
Feature Feature Feature
Operating System
OpenFlow API
OpenFlow Switch OpenFlow Switch OpenFlow Switch

24. Just like APIs in the programmable web, the
more apps that depend on them, the stickier
the SDN Controller is.

25. App A App B App C App D
Datacenter Operating System
SDN Controller A SDN Controller B
OpenFlow API
packets OpenFlow Switch packets
OpenFlow API
Flow Table Flow Table Flow Table

26. Expanding new features running elsewhere in
the datacenter increases the agility of the
software-defined network.

27. App A App B App C App D
Datacenter Operating System
Northbound API
SDN Controller A SDN Controller B
OpenFlow API
packets OpenFlow Switches packets

28. End of Quarter Intrusion Energy
Route to Sandbox
SLA Detection Management
Datacenter Operating System
Northbound API
SDN Controller A SDN Controller B
OpenFlow API
packets OpenFlow Switches packets

29. SDN controllers are made by multiple vendors,
each with their own northbound APIs. New
features have to work with every controller.

30. App A App B App C App D
Datacenter Operating System
Northbound API A Northbound API B
SDN Controller A SDN Controller B
OpenFlow API
packets OpenFlow Switch packets

31. A few examples of northbound APIs

32. http://www.openflowhub.org/display/floodlightcontroller/
Floodlight+Documentation
http://docs.openstack.org/api/openstack-network/2.0/content/
http://www.vyatta.com/downloads/documentation/VC6.3/
Vyatta_RemoteAccessAPI2.0_R6.3_v01.pdf

33. APIs IN THE
SDN REVOLUTION

34. The software that defines the network does
so via APIs.
While virtualization is a systems model, APIs
are an abstract model.
An API is a programming model.

35. One thing that is significantly different from
APIs in the programmable web is that in SDN
each API has multiple instances.
This is because each controller from a given
vendor is implementing the same API but
there are many copies of that controller
running in the same environment.

36. One thing that could move SDN forward is to
have a single API that interoperates with each
of the various SDN controller APIs.

37. App A App B App C App D
Common Northbound API
Datacenter Operating System
Northbound API A Northbound API B
SDN Controller A SDN Controller B
OpenFlow API
packets OpenFlow Switch packets

38. What if we had a single view of the
software-defined network?

39. Policy-based Intrusion Network
Application QoS
Routing Detection Management System
Common
Northbound API
SDN Controller A SDN Controller B
OpenFlow Switch OpenFlow Switch OpenFlow Switch
OpenFlow Switch OpenFlow Switch

40. This is an enormous opportunity for the
DevOps movement.
You get control over the network on top of
your existing control over the servers.
And you will speed the disintegration of NMS.

41. How far could we take the system towards
perfecting user experience of our services?

42. Policy-based Intrusion Network Management
Application QoS
Routing Detection System
Common
Northbound API
SDN Controller A SDN Controller B
OpenFlow Switch OpenFlow Switch OpenFlow Switch
OpenFlow Switch OpenFlow Switch

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45. THANK YOU
Questions and ideas to:
@sramji
@brianpagano