Need to get connected with SDN

Hey all, we have created a connection with SDN. After getting introduced to SDN in my last post, let us find out the worth of SDN. In the last post, I told you a short story of Tom-Jerry, where on Jerry’s birthday, Tom gives a surprise visit to Jerry and how Tom is extremely happy, as he had the best journey, all thanks to Google Maps. Tom expresses his happiness to Jerry and they start discussing those old days when visiting Jerry was so hectic. While Tom remembers some of his bad journeys, let us get along with him and try to analyze the hurdles, also try to find out the need of SDN.

This is how Tom and Jerry’s houses are located. The path in orange is the best path to reach Jerry’s place. Back in those days, Tom used to follow the sign boards on the roadsides to get directions.


Both laugh aloud remembering a time when Tom had 5-6 friends with him and they were in this big car. After covering half of the distance, they had to stop because the road said ‘Only Two-wheelers’, when they still tried to enter the road, traffic police caught them and let us not get into further details. So, had there been Google Maps, it would have shown about road policies like the speed limit, a number of lanes, toll prices, the size of vehicles allowed etc. earlier to Tom, so that he could have taken a decision based on these policies to take an alternative path or get some more bikes. Imagine what a task it is to maintain sign boards for such policies, to the road administrator. We all know, a network is made of policies, each device is configured differently, has ACLs, routing protocols, VLANs and is managed independently. But, SDN greatly simplifies the network devices themselves, since they no longer need to understand and process thousands of protocol standards but merely accept instructions from the SDN controllers. It also simplifies the task of network managers, by making policy driven decisions. SDN also gives network managers the flexibility to configure and manage network resources via dynamic SDN programs. This makes network programmable.

Tom suddenly realized that all these hardships he faced were back then, but now the city looks like this.


Woah..!! the city has developed to a whole new world. Tom takes a sigh of relief, as he has Google Maps now.

With the advent of virtualization and cloud computing, the network map is no more static. Also, traditional networks are not able to scale, due to social networking sites like Facebook, Twitter, Google etc. E-commerce sites like Amazon, Flipkart, Ola etc introduces a huge number of users in the network every day. VM migration, mobile devices coming and going, make rapid changes in the network. SDN provides dynamic reaction to changing network and go hand in hand with cloud computing and virtualization.

Wow, SDN seems like a perfect solution with no cons 😛 But, we are aware that major problem with centrally controlled systems is single-point-failure. To avoid this, the centralized SDN Controller can be distributed so that several controllers can control the network, which is like load balancing the traffic to many controllers.

As we have seen, SDN provides an abstraction layer between software and low-level hardware resources. It has the ability to adapt in today’s immensely fast growing networking hub and makes network programmable. Now, you might feel that SDN definitely is the next big thing in computer networking.

Creating connection with SDN is surely worth it.

Happy networking with SDN…!!!

#networking #SDN #SDNcontroller #softwaredefinednetworking

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