SDN - The New Disruptive Technology
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Posted on: Oct 06, 2014
By Rodney Wise
Director of Technology Selection
Walker and Associates
In terms of efficiency and network evolution, the move in the 1980s and 1990s from Channel Associated Signaling (CAS) to Common Channel Signaling System 7 (CCSS7) seems to have had as much impact as Software-Defined Networking (SDN) implementation will in coming years. Prior to SS7, 64kb voice channels were nailed up along each path of the call in anticipation of the call being established. If the called party wasn’t home or already on a call, the 64 kb channel was wasted throughout the entire network during the time it took to recognize the called party was busy.
After SS7 implementation, out of band signaling determined the availability of the called party and prepared all network elements along the route for the call prior to establishing the 64 kb channel throughout the network, therefore saving tremendous bandwidth in the entire network. Now, SDN similarly provides network control separated from the data forwarding plane, making a more dynamic and flexible network. Software- Defined Networking is transforming network architecture, and proving to be disruptive in its applications.
In the SDN architecture, the control and data planes are decoupled, network intelligence is centralized, and applications are removed from the network infrastructure. As a result, the network gains much needed configurability and control. This allows network administrators and engineers to configure flexible networks that can quickly adapt to new service requirements. Cloud services, virtualization, and accelerating mobile device growth are driving these new service requirements and leading the re-architecture of the network. When properly designed and implemented, the SDN architecture provides centralized management and control of multi-vendor networks, improved automation through advanced provisioning, delivery of new services without the need to configure each network element, and simplified configurability through a common user environment.
When a packet arrives at a switch in a conventional network, the switch’s firmware has been preconfigured to know where to forward the packet. The switch sends every packet going to the same destination down the same route and treats all the packets the exact same way. Usually, this conventional network is built in hierarchical tiers that behave in a high level view similar to telephone exchanges. Making changes to this fixed network requires an in-depth knowledge of each network element technology and existing configuration. In addition, network engineering time is required to manage fixed network changes, adding to expenses. SDN provides a much more dynamic network capable of rapid configuration changes for new revenue-generating services.
SDN moves control from individual network elements into special SDN controllers. These SDN controllers provide complete visibility and control over the network. Since these controllers are the configuration tools, they can ensure that access control, traffic engineering, quality of service, security, and other policies are enforced consistently across the network infrastructure. Network operators benefit from reduced operational expenses, more dynamic configuration capabilities, fewer errors, and consistent configuration and policy enforcement.
In conclusion, anything as a service, in addition to virtualization and mobile device growth, has created a need for network evolution. SDN provides the architecture to rapidly respond to new service demands on the network. SDN offers the intelligence to allocate resources on demand, scalability, and support for more virtualization. In the area of efficiency and network evolution, SDN is creating an equivalent technology disruption that SS7 implementation did two decades ago And, SDN is just the beginning of a more software driven network that will create even faster innovation and more frequent network transformations.