What is SDN?
Software-defined networking (SDN) is an approach to networking in which control is separated from hardware ( control decoupled from forwarding plane) and given to a software application called a controller.
What are the issues with today’s networks?
- Networks are static: Today’s networks are static; e.g introducing new switches or moving any network element or routers need a lot of involvement of IT in terms touching a lot of switches, routers, firewall and update ACLs, VLANs, QoS using device level management tools. The software version, hardware version etc need to be taken into account. Therefore today’s network are mainly static. On the hand the network needs are dynamic and growing. Applications today reside on multiple virtual machines ( VMs). VMs migrate to balance the server workloads causing the traffic pattern to change dynamically.
- Inability to Scale: Data centers are growing in big numbers and so does their connectivity requirements. Companies such as google and Yahoo are depending on the efficiency of their data centers’ connectivity to provide fast speed processing to the users. As the network grows, the network elements grow tremendously rendering it very difficult for the IT to manage the network manually.
- Vendor dependence: Service Providers have to depend on the vendors , their product life cycles and roadmaps to deploy new services.
How can SDN Help?
SDN makes the network control decoupled from forwarding and makes it programmable. By this decoupling, IT managers will have full control on the configuration, optimization, management via dynamic SDN programs. This programs are written by service providers themselves and they don’t have to depend on the vendors to develop the products as per their roadmaps. This enables the organization to quickly roll out the services, efficiently control network resources from a central place and cope dynamically with the dynamic demands of the network which otherwise is not possible with the static networking.
What is Open Flow ?
Open Flow is a protocol through which SDN will be standardized; It is the protocol through which the forwarding plane will be controlled by the Control layer.