Software Defined Network (SDN) v1.0 & v2.0
As we discussed earlier, OpenFlow and SDN are different, though both have a common origin – Martin Casado. While OpenFlow can be defined as the protocol for sharing of the routing / forwarding table between the control & the forwarding planes, the SDN on the other hand is the complete ecosystem. The OpenFlow can be taken as an ancestor of the SDN, from the same founder, but is just a subset of the larger domain called SDN. Though the core concepts for both are similar, that the controller is centralized, control & data planes are separated. The properties defined by the open networking forum for the SDN are as under;
- It’s programmable
- It’s agile and centrally managed.
- It’s vendor neutral or what we call as open standard.
And that translates the key benefits of SDN over conventional networks as;
- Virtualization – multi tenant for single resource and multiple resources makes the same infra available for multiple locations / applications & users.
- Programmable – rerouting the traffic and reorganizing the resources, as per the date / day / time / event / need based etc.
- Automation – distributed architectures re programmed as per the need, reduces the operational cost.
- Orchestration – managing huge number of devices automatically with unified management.
- Non-proprietary open standards.
And this statement can explain the difference between them – All NRIs have Indian origin, but all NRIs don’t stay in US. Some stay in US, some in Australia, some in EU, some in Middle East Asia, some in Africa, and so on. Similarly, SDN can be configured on OpenFlow protocol, but there are many other protocols too, for SDN. SDN is multiprotocol system which, can not only work on OpenFlow, but IETF, XMPP (Juniper), ALTO (Application Layer Traffic Optimization), PCEP (Cisco), BGP-LS, OnePK , PCE, ForCES, SMTP, OpFlexand so on.
This new age concept of SDN, when many other protocols apart from OpenFlow started accepting the SDN API, changed the original SDN model from the original Open Networking Forum Model. Between the control plane and the forwarding plane, the industry developed a protocol plug-in concept on the (SAL) Service Abstraction Layer wherein any of the above mentioned protocols would fit in and give the programmability option or the SDN functionality. This new version of SDN was called OpenDaylight SDN or the SDN v2.0. and the entire work on this is being done through Linux foundation, instead of Open Networking Forum.