Software-Defined Networking (SDN) is a dynamic, manageable, cost-effective, and adaptable architecture, ideal for today’s high-bandwidth applications. It decouples the network control from forwarding functions making it directly programmable and rendering the underlying infrastructure to be abstracted for applications and network services. The SDN architecture is:
- Directly programmable: Decoupled from forwarding functions, the network control becomes directly programmable.
- Agile: Abstracting control from forwarding lets administrators dynamically adjust network-wide traffic flow to meet the changing needs.
- Centrally managed: Network intelligence is (logically) centralized in software-based SDN controllers, maintaining a global view of the network, rendering a single and logical switch to applications and policy engines.
- Programmatically configured: SDN lets network managers configure, manage, secure, and optimize network resources faster via dynamic, automated SDN programs.
- Open standards-based and vendor-neutral: When implemented through open standards, SDN simplifies network design and operation because instructions are provided by the SDN controllers instead of multiple, vendor-specific devices and protocols.
Computing Trends are Driving Network Change
SDN addresses the limitations of the static architecture, of conventional networks, which is not capable of meeting the dynamic computing and storage needs of today’s data centres, 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 highly 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, fuelling 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, thereby discouraging network changes.
- Inability to scale: The approach of link oversubscription to provision scalability is not effective with the dynamic traffic patterns in virtualized networks—a problem that is 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.
I believe NSX Network Virtual Platform is the next generation for Network. In fact, we need to mention NSX is the virtualization platform for SDDC software designed data centre. NSX is one of the popular topics of discussions these days especially with the increased move from static data centre networks to more dynamic ones (SDN style). NSX (VMware) and ACI (Cisco) represent a developed version of data centre SDN which offer several benefits and features including but not limited to, simplified provisioning, simplified manageability, centralized control, distributed switching, more application and VM aware networks.