What is software defined network (SDN)
Software-defined networking (SDN) is an approach to computer networking which evolved from work done at UC Berkeley and Stanford University around 2008.SDN allows network administrators to manage network services through abstraction of lower 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). The inventors and vendors of these systems claim that this simplifies networking.
SDN requires some method for the control plane to communicate with the data plane. One such mechanism, OpenFlow, is often misunderstood to be equivalent to SDN, but other mechanisms could also fit into the concept. The Open Networking Foundation was founded to promote SDN and OpenFlow, marketing the use of the term cloud computing before it became popular.
Computing Trends are Driving Network Change
SDN addresses the fact that the static architecture of conventional networks is ill-suited to the dynamic computing and storage needs of today’s data centers, campuses, and carrier environments. The key computing trends driving the need for a new network paradigm include:
Changing traffic patterns: Applications that commonly access geographically distributed databases and servers through public and private clouds require extremely flexible traffic management and access to bandwidth on demand.
The “consumerization of IT”: The Bring Your Own Device (BYOD) trend requires networks that are both flexible and secure.
The rise of cloud services: Users expect on-demand access to applications, infrastructure, and other IT resources.
“Big data” means more bandwidth: Handling today’s mega datasets requires massive parallel processing that is fueling a constant demand for additional capacity and any-to-any connectivity.
In trying to meet the networking requirements posed by evolving computing trends, network designers find themselves constrained by the limitations of current networks:
Complexity that leads to stasis: Adding or moving devices and implementing network-wide policies are complex, time-consuming, and primarily manual endeavours that risk service disruption, discouraging network changes.
Inability to scale: The time-honoured approach of link oversubscription to provision scalability is not effective with the dynamic traffic patterns in virtualized networks—a problem that is even more pronounced in service provider networks with large-scale parallel processing algorithms and associated datasets across an entire computing pool.
Vendor dependence: Lengthy vendor equipment product cycles and a lack of standard, open interfaces limit the ability of network operators to tailor the network to their individual environments.
What I see the Software Defined Networking (SDN) as is the Hypervisor for the Network: “SDN is going to be as big as the Hypervisor was for x86”:
How I see software defined networking (SDN) is in a simpler way SDN is what hypervisor’s have done to the x86 platforms over the past 10 years, SDN to me should be looked at as the method to disconnect or decouple the physical network hardware layer for the network and the logical traffic and rules that run on that physical network. I.e. think of it as a SDN equals the Hypervisor for the Network (all of the network from the mobile client to the core cloud datacentre).
SDN doesn’t have to just be switching either it can be all the network from switching, load balancing, access control, firewalls, mobile connection, virus and IPS, SDN can be used for the whole network.
Networking of the future could be simple, configuring your network could be as easy as dragging and dropping icons on a desktop or installing an application from itunes, really could take seconds to create a network for 10 devices or 1 million devices. No need any more to worry about thinking about IP masking and routing and limits because of the physical limitations and cables.
What I would say today is everyone should be investigating SDN across their network infrastructures from the mobile network through to the cloud data center.
Using SDN to automate and deliver service will become the most cost efficient and simplest Maner without thinking physical limits having closely stack based physical / logical solution, no more top or rack or end or row.
Think of the physical cost saving also power, space, upgrades and redundancy. Can we afford to not look at SDN should be the question we are all asking ourselves?
Some interesting links and possible useful links to help in your research.
Check out all the normal vendors, such as Cisco, VMware, F5, Juniper Networks,
Open Networking Foundation
Butler, Brandon: 10 network virtualization, SDN and data center companies to watch, Feb 2013
Vance, Jeff: Ranking the Top 10 Software Defined Networking Startups, Sept 2013
Berndtson Chad: 25 Software-Defined Networking Players to Know, April 2012
King, Rachel: Incumbents Race to Define SDN Before it Defines, or Disrupts, Them, Nov 2013