SD-WAN Explained In simple terms (SD-WAN) could even be a merger of two areas of technology. An old and a comparatively new one. It takes the new concept of Software Defined Networking (SDN) and applies it to the normal enterprise wide area network (WAN).
Let's take a better check out this paradigm. WANs haven't changed much within the past 20 years. Stagnant technologies like T1, Frame Relay, ISDN, ATM and MPLS are still almost an equivalent as after their introduction. the matter with this revolves round the increased bandwidth requirements of companies as they move to an “as-a-service” architecture. SaaS, PaaS, IaaS, and other cloud services have dramatically changed the normal 80/20 rule of networking.
The 80/20 rule states that 80% of network traffic within a corporation remains local while 20% is offsite. We are now seeing an entire reversal towards 20/80. Services like Office365, AWS, Azure, and Google Cloud are taking up from what were traditionally applications hosted at data center.
SD-WAN includes the subsequent basic concepts:
Separation of the control plane from data plane
Consolidation of disparate connectivity sources into larger, virtualized and secure links
Provide application knowledge and intelligence to prioritize applications instead of just packages
The separation of the control plane from the data plane could even be a crucial element that lies at the middle of SD-WAN. It allows a controller to holistically inspect the performance of the whole network instead of each router reacting only by supporting its view. Only by having information about the state of the end-to-end network can optimal path selections be made and consistent global policies are often defined.
Link aggregation has been an important a part of networking for several years, for instance , the 802.3ad standard was introduced in 2000 (Link Aggregation Control Protocol). before that, from the first until the mid-1990s, providers of individual network equipment used proprietary algorithms and controllers to aggregate multiple links thanks to bandwidth limitations. the most caveat being that each one links had to be an equivalent standard and therefore the same speed to interact within the beam.
Recent advancements have brought with them the likelihood of grouping links that are of various technologies and speeds. This made it possible to incorporate Internet Ethernet circuits, MPLS circuits and even the utilization of wireless technologies like LTE. This capability, while critical for increasing bandwidth, also provides true redundancy through the incorporation of wired and wireless connections, and even circuits from different carriers.
The concepts of control plane separation and link aggregation are where the primary generation SD-WAN vendors left off. With the incorporation of machine learning and another factor of SDN, application intelligence, you see the advantages of subsequent generation begin. the power to quickly discern and manage new application flows without the hierarchical quality of service configuration required by first-generation vendors and routers provides a selected administrative advantage. The Network Engineering department can easily identify new applications and enforce policy supported business logic instead of fixing ACLs to mark, queue, and control traffic.
Second Generation SD-WANs add intelligence beyond traditional networks and first generation SD-WANs to need application knowledge and machine learning to optimize network health to maximise user experience with applications, instead of just making decisions about packages. it's often that policies are often set for supported applications, locations, priorities - business terms - instead of being translated into low-level technical jargon.