Deployment Guide
9
3 Product Features – SDN/OpenFlow and DNOS-OF
3.1 Overview – What is SDN?
The physical separation of the network control plane from the forwarding plane where a control plane
controls several devices. Software-Defined Networking (SDN) is a networking architecture that is dynamic,
manageable, and adaptable, making it useful for high-bandwidth dynamic applications. This architecture
decouples the network control and forwarding functions enabling the network control to become directly
programmable and the underlying infrastructure to be abstracted for applications and network services.
The OpenFlow™ protocol is a foundational element for building SDN solutions.
Some attributes of SDN architecture are:
Directly programmable: Network control is directly programmable because it is decoupled from
forwarding functions.
Agile: Abstracting control from forwarding lets administrators dynamically adjust network-wide traffic
flow to meet changing needs.
Centrally managed: Network intelligence is (logically) centralized in software-based SDN controllers
that maintain a global view of the network, which appears to applications and policy engines as a single,
logical switch.
Programmatically configured: SDN lets network managers configure, manage, secure, and optimize
network resources very quickly via dynamic, automated SDN programs, which they can write themselves
because the programs do not depend on proprietary software.
Open standards-based and vendor-neutral: When implemented through open standards, SDN
simplifies network design and operation because instructions are provided by SDN controllers instead of
multple, vendor-specific devices and protocols.
3.2 Overview – What is OpenFlow?
The OpenFlow protocol is one instance of an SDN architecture, based on a set of specifications
maintained by the Open Networking Forum (ONF). At the core of the specifications is a definition of an
abstract packet processing machine, called a switch. The switch processes packets using a combination of
packet contents and switch configuration state. A protocol is defined for manipulating the switch's
configuration state as well as receiving certain switch events. Finally, a controller is an element that speaks
the protocol to manage the configuration state of many switches and respond to events.
More Information on the verview and genesis, current state of protocol:
https://www.opennetworking.org/images/stories/downloads/sdn-resources/white-papers/wp-sdn-
newnorm.pdf
OpenFlow from Flowgrammable website: http://flowgrammable.org/
OpenFlow from Open Networking Spec website:
https://www.opennetworking.org/sdn-resources/openflow
Traditional non SDN networks vs SDN networks