{"id":84,"date":"2019-11-08T16:14:42","date_gmt":"2019-11-08T10:44:42","guid":{"rendered":"http:\/\/bluemap.co\/blog\/?p=84"},"modified":"2022-01-07T12:02:35","modified_gmt":"2022-01-07T12:02:35","slug":"software-defined-networking-why-it-matters","status":"publish","type":"post","link":"https:\/\/bluemap.co\/blog\/2019\/11\/software-defined-networking-why-it-matters\/","title":{"rendered":"Software Defined Networking: Why it matters?"},"content":{"rendered":"\n

We have been seeing IT for the past 20-30 years and\nhow it has evolved. Many new applications coming up in the recent past and more\nand more things moving towards the internet. Business needs have grown\ndynamically. But is our network agile enough to support it? Has it changed over\nthis period? Somewhat yes as the vendors have focused more on building new and\npowerful devices to meet the needs, but that comes with a heavy CAPEX and OPEX\nfor the clients. Has the management of those devices changed yet? The answer is\nNO. <\/p>\n\n\n\n

Consider you have 10, 100 or 1000 nodes in your\ncompany network that means you are managing equal number of control planes.\nThis leads to problems like that if anything has to be changed in the network\nthen time for execution is very high extending up to weeks or months in some\ncases. Moreover the network is vendor dependent i.e. if the network requires a\ncertain feature to be present and the vendor does not provide that feature in\nthe existing devices it leads to an increased investment thereby increasing\nCAPEX and reducing profitability. The network architecture needs to change.<\/p>\n\n\n\n

Back in 2007 Stanford University started a program\ncalled the Clean Slate. The idea behind this was to make the participants think\nof how they would have designed the internet starting from scratch. Software\nDefined Networking or SDN was born then. The idea was to decouple the control\nplane from the data plane. The control plane should be implemented on a\ncentralized server and all the applications can access it directly to program\nthe network behavior or to extract network information. The control plane in\nturn programs the data plane of each devices leading to decreased time for\nexecution. Moreover SDN is an open network having open source network devices\nthereby reducing the vendor dependency immensely.  <\/p>\n\n\n\n

The figure below shows how a Software Defined Network\nis different from a traditional network. \nApplications communicate with Controller which resides on a central\nserver using NorthBound APIs (eg. REST). The controller then communicates to\nthe programmable network element using some SouthBound protocols (eg.\nOpenflow). The network elements fulfill the request from the controller. One\nthing to mark here is that Openflow is a part of the SDN story and not the\nwhole story.<\/p>\n\n\n\n

This type of network architecture gives us two important benefits:<\/p>\n\n\n\n

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