Software Defined Networking

Software Defined Networking

Software Defined Networking is an approach to computer networking that allows network administrators to manage network services through abstraction of higher-level functionality. This is done by decoupling the system that makes decisions about where traffic is sent (the control plane) from the underlying systems that forward traffic to the selected destination (the data plane).

Pillars of SDN:

  • Separation of Control and Data Plane
  • Centralized Controller
  • Programmability
  • Open interfaces
  • Abstraction
Fig 7.3/1: SDN
SDN Application
Programs connected to SDN Controller via northbound interface.
SDN Applications sends SDN Controller information about desired network behavior and network requirements.

SDN Northbound Interfaces (NBI)
NBIs connects SDN Applications with SDN Controller. NBIs interfaces should be vendor neutral and open.
Main responsibilities of NBI are:
  •     provideing network view to SDN applications
  •     provideing network behavior and requirements to SDN Controller

SDN Controller
Logically centralized controller is responsible for translating desired network behavior
from SDN Applications to phisical network. SDN Controller provides abstract view of the network to SDN Applications.

SDN Control to Data-Plane Interface (CDPI)
CDPI is interface between Phisical network and SDN Controller. CDPI same as NBI should be vendor neutral and open.
Main responsibilities of CDPI are:
  •     control of operations
  •     reporting of statistics
  •     events notifications