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What’s the Difference between Cloud Computing and Software Defined Networks (SDN)?

Posted by QuoteColo on December 08, 2015 - Updated on February 20, 2023

The differences between Cloud Computing and Software-Defined Networks (SDN) are best explained by their functional goals:

Cloud computing functions to provide users with access to critical data on an anytime, anywhere scale, while the goal of a Software-Defined Network (SDN) is to allow a network admin to shape, construct and manage network resources – traffic, bandwidth etc. – from a central console without having to deal with modifying individual pieces of network hardware.

  • The cloud is a backbone computing infrastructure designed for easy access to data via remote servers
  • Software Defined Networks are an approach to networking which allows admins to more accurately allocate network resources via a central console controlling virtualized infrastructure

Cloud Computing – Cloud computing is the process of storing and accessing data on remote servers accessed via a direct Internet connection. Rather than using a server on the local network to store data, cloud computing links the user with a remote server via Internet access for 24/7/365 access to critical data. For most people, their interaction with data in the cloud is via mobile apps and platforms like Google Drive, Dropbox and Office 365.

what is cloud computing

Software-Defined Networks (SDNs) – Software-Defined Networks, or SDNs, are a centralized approach to networking, allowing network administrators to manage network resources and services via an abstraction layer – in most cases a digital dashboard or console – in order to give them a higher level of network functionality and more granular control over resource allocation. An SDN creates a functional separation between the control plane of the network and the data plane, which allows network administrators to easily change the rules for the exchange of information in any part of the network, as needed, and even using programmable automation, without having to worry about making changes to individual connected devices. A regular network might use specialized solutions such as a firewall or load balancer, but an SDN manages the data plane by deploying an application that uses the controller to do so. Rules for handling data are sent to the network switches from the controller, and switches request instructions for handling data from the controller as needed, and send back information about traffic being handled. This creates a much more flexible and efficient method for managing network traffic loads. The image below illustrates how an SDN works.

what is SDN

Technologies like software-defined networking and cloud can bring major improvements in efficiency and adaptability to your IT systems. Now that we have the differences spelled out, let’s take a look at how the combination of cloud computing and software defined networks are digitally empowering our society, as well as the unique challenges they present.

SDN and Cloud: Combined Infrastructure Energy Savings

Multiple reports have cited that the combined use of SDN and cloud infrastructure has routinely presented approximately a 40 – 50% energy savings, along with CAPEX cost reductions and nearly 40% OPEX savings via automation. The implications of cost savings, certainly when it comes to large-scale organizations or municipalities of various sizes, will play a large role in how both proceed with their core infrastructure needs.

Cost Savings with SDN and NFV

While SDN and cloud play into one another, we would be remiss not to mention NFV as a driving focal point for network cost reductions for SDN cloud. NFV, or network functions virtualization, is the process of virtualizing network hardware with the express goal of eliminating clunky hardware in favor of high functioning network equipment capable of varying the load for large-scale virtualized properties.

Traditionally speaking, one of the main drivers of cost with physical network hardware is visibility. As noted via an excellent InfoWorld article on the role of SDN in effective cloud computing:

“When accounting for IT and data center costs, a large percentage of capital expenditures are actually allotted to bandwidth, storage, and other operational resources. To be properly assigned, these operational resources need a correct method for planning and eventual deployment. Otherwise, these resources may become misallocated — wasting time and money, potentially on a large scale.”

Physical hardware, due to lack of visibility on how resources are allocated, has the tendency to waste time and money. It’s estimated that nearly 70% of operational servers running in a data center are either running woefully under capacity – using 25% of their compute power while using 100% of their energy requirements – or are tasked with processing too heavy a load for their computational power resulting in poor performance. Both scenarios, on the scale of long-term data center operations, cost a pretty penny.

cloud computing vs sdn

One of the tricks to curing the issue is virtualization – yet virtualization only works to an extent. While virtualization of hardware resources allows network admin’s to more properly monitor and manage server resources, it can also create uncalled for VM’s to process load on an existing VM thought to be overloaded. Much like lack of visibility with physical hardware, the spinning up of unneeded VM’s also will cost a pretty penny over an extended period of time.

Through NFV and SDN, the issue of faulty costs is removed by separating the data operations of a VM with the control panel – the abstraction layer – of that VM. With the utilization of smart API creation and command line interfaces, the ability to define rules for data flow increases across both virtualized hardware and physical devices like switches. All of this, in turn, enables network admins to more closely monitor data flow across the network via the allocation of needed resources where needed.

Cost Savings and Data Allocation Give Way to Mobile, Smart Cities and Advanced Networks

The two major benefits of cloud computing and SDN (coupled with NFV) are cost savings and the smarter allocation of resources within a network via the division of data and control planes. Outside of the stated major benefits, the combination of cloud and SDN will produce some additional benefits:

Mobile Communication: According to a 2013 study conducted by Cisco, by 2020 50 billion devices are expected to be connected to the Internet. 50 billion connected devices will require large-scale real-time data evaluation to ensure pipes stay open when traffic surges across the globe. To do this, cloud infrastructure will have to expand under the smart management of resources provided by SDN and NFV. The keys to successfully managing this growth will be dynamic, large-scale bandwidth, matched with high-capacity and low latency throughput to ensure quality of experience.

Smart Cities: With the open availability of cloud, SDN, NFV and IoT, smart cities are already arising to meet functional demand. To improve basic day-to-day city operations, municipalities will have the ability to install smart solutions via multiple avenues (BOO, BOT, OBM and BOM). Once installed, smart city applications will help:

  • Find parking quicker through real time applications
  • Connect to Wi-Fi regardless of location
  • Build sustainable and energy efficient real estate
  • Provide city controllers with dynamic real-time information on weather, traffic, local news, etc.
  • Provide smarter response to emergencies through highly accessible streaming data collected via social networks and sent via larger bandwidth pipes

High Speed Advanced Networks: As a result of smart cities and smart organizations coming online, one of the byproducts must be 5G and beyond networks. To support traffic, devices and sensors connected to a given network, both local and global communications infrastructures need to evolve, grow and adapt. While it can be said this evolution is in the hands of ISP’s, it can also be argued SND and cloud will force the hand of evolution.


The distinctions between cloud and SDN continue to blur. In most cases, the use of in network or cloud based workloads is a choice dependent on performance needs and costs. With the current state of computing, more and more routine and heavy load functions are being carried out either within a network or within a cloud infrastructure. With both solutions boosting performance and lowering costs, it only makes sense that more computing needs would be carried out within network or cloud infrastructures.

As more and more actions are processed via network or cloud, the question at hand will turn to latency. For the lines to blur between network and cloud even further, the trick for network admins will be to maintain computing power via proper management of millions of software transactions. If SDN and cloud can keep that management constant with ultra-low application latency, the distinctions between SDN and cloud will continue to fall away.

The combination of SDN and cloud tech will bring about massive changes in our society, both in terms of business organizations and municipalities. While the mingling of SDN and cloud are currently providing massive cost savings for organizations and municipalities, as illustrated, the end point is capable of producing so much more. From smart cities, to advanced networks and increased mobile communication, SDN and cloud carry with them the promise of a true digital society.

If you are interested in learning more about SDN and cloud hosting, please shoot us an email ([email protected]) or call us at 888-400-5732.

Categories: Cloud

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