Introduction to SDN (Software-defined network)

Our Topic is SDN, It stands for Software-defined networking highly correlated with NFV, SDN is a big thing in the IT and telecom industry l am going to build your concepts on SDN technology using very simple graphics and the concepts which I am going to tell you are of use for everyone which is working in IT or telecom or NetworksWhile NFV is all about building virtual platforms, SDN is making IP networks much more programmable so that packet routing is possible with lots of flexibility and agility. As shown here, SDN is based on the concept of separating the Brain and control plane for traffic routing, This separation of Brain and control plane makes SDN a very very powerful tool for customizing networks on the fly with SDN, You can provision new bandwidth and define traffic failovers just like never before now, Let’s start our journey with SDN There is a lot of confusion between NFV and SDN, Don’t worry, we are going to clarify both the technologies in a very very simplified way using the real-life examples till now. Since NFV is all about Three main Concepts: Softwarization, Virtualization, Orchestration, and automation. SDN is a different animal, It is all about networking control functions for routing policy definition. This entire thing is done in a very very automated way. With SDN, what we are going to do We are going to ensure the IP Network reachability is going to happen well in Time. Both SDN and NFV architectures are going to use network abstraction, But they do is totally in different way SDN provides a new level of programmability and abstraction to the Network layer which plays a phenomenal role in Automating the networks. Let’s take deep dive on SDN understand how it works just to see the Building blocks which represent the NFV host multiple Applications. Just like you can remove, replace or keep a new tenant in Build. Similarly, you can host applications in NFV as well you can see traffic on road representing SDN whose main responsibility is to carry traffic to the right destination in a very very Automated way. First, Let’s understand why we need SDN? How it is helping…Well, We know the NFV helps in Virtualizing networks which help us in rapid deployment. ultimately reduce our deployment time of New Service / New NodesNow NFV does it in few seconds .. but what about network reachability network connectivity and reachability is the real problem, For any new node or new service, We need multiple things such as the IP Allocation, the Bandwidth Allocation, the Policy Opening, the Routing changes actually, We need to do End to End Reachability and for doing that it takes a lot of time .. it takes a lot of time to prepare the design, to execute the changes and we need to do in every router, every switch that is also prone to mistakes, Net, for doing the network reachability piece, we take few days, few weeks Ultimately, even if the NFV resource are available but we can’t launch the new service or we can’t make the new node live because our network reachability is not doneThe SDN is going to help us specifically out here, Let’s understand how SDN works, in our traditional network where traffic is moving between various Switches and Router in order to reach the final destination SDN changes how networking is fundamentally done. Instead of having a network intelligence that is distributed in every device ( i mean to say every router and switch applying its own brain )SDN aims to centralize the Brain .. SDN aims to centralize command and control into a central node and It’s going to distribute the entire thing in the different control plane and in a different data forwarding planet’s understand, how this different plane works out there The 1st one is the Data Plane, We also call it as Forwarding function or Forwarding plane.In a traditional network, In traditional router and switches, There are multiple nodes which are connected to each other all these multiple router and switches, they are connected to each other via line card and the links running between these line cards this is where the data is actually moved from one device to another, As visible on-screen traffic is going all the way from Router A to Router B to Router C to Router D ..Traffic is moving all the way from Left to the right that’s how the packets are flowing here, We call it as Data or Forwarding PlaneThe next one is control plane. Well in a traditional network, The role of the control plane is to make routing decisions. Every router is having its own brain… You can see the brain in this orange color which is like rotating out thereEvery router apply its own brain to decide the best path to route the traffic these routing decisions are taken on basis of the routes configured in the router and routes learned from the adjacent nodes or adjacent routers an example, In a traditional network, Router A decides to route the traffic to router B on basis of Brain applied by itself i.e. Router AI mean to say the router A is taking the decision where to route the traffic since Router A doesn’t know what’s happening in the life of subsequent routers such as C or D, This can be the point of concern mean to say , if there is some problem with Router D, Router A never comes to know, because Router A is not speaking to Router D directly going via B, C and then ultimately reaching router D. And if there is a problem with D, A will never come to know and A will keep on bombarding the traffic in the same direction, it will never route traffic to a better pathThere has to be someone, There has to be absolutely someone .. who is keeping end to end an eye on complete network and take holistic decisionThat’s the power of SDN where we are going to bring these resiliencies into the Network. The last one is the Management Plane. Now, In a traditional network, This is used for performing Operation maintenance of the network. I mean to say you can do the configuration, You can get the reports you are actually running the network out there, For example, We use management plane to fetch reports, Perform Configurations, Get Alerts and Alarms.