How to Choose Open Source SDN

By CIOReview | Wednesday, June 29, 2016

Software-defined Networking (SDN) community has disrupted the network industries for decades where big-named vendors ventured into engineering of their networks. The need of enterprises to innovate the existing SDN framework to suite necessity, fostered development within the SDN community, giving rise to many open source projects. This openness in SDN software projects carves its way towards gaining high efficiency and with reduced cost. It is important for C-level executives to evaluate how these open source products can help them meet their organization’s objectives. 

Attributes of Open SDN:

Open SDN is an umbrella which encompasses various network technologies, making networks agile and flexible. These network technologies are empowered with standards, software, application interfaces/ software development kits, and hardware.             

Open Standards:

Generally, Open Standards are specifications for hardware and software, developed and maintained through a shared process. These standards are freely and publicly available, facilitating interoperability between various products and services. These open standards or protocols are non-proprietary and is applicable in heterogeneous environments. For instance, Cisco’s open standard proprietary protocol solution ‘onePK’ enables customers to develop SDN-type centralized applications onto its solution. Open Standards are included in the areas of Packet Processing where it is seen that non-traditional associations—Institute of Electrical and Electronics Engineers (IEEE), Metro Ethernet Forum (MEF) and many more continue to operate interoperability between new networking software and traditional networks.

Open Source Software:

Open source software allows individual to leverage source code and modify the existing software. From the SDN central perspective, a SDN Open Source Software embeds data plane software like ‘Open vSwitch’, control plane software like ‘OpenDaylight’ and ‘OpenStack’. These open source software’s are released under Free and Open Source Software (FOSS) licensing. These softwares promote public collaboration and sharing, as software copyright holders license the right to study, change, and distribute the source code.

Some of these open source SDN projects are controlled by a single company, which extracts more tax from the entire ecosystem that leverages their open source code. Exemplating Oracle, which drove its product ‘MySQL’ to dual license that compelled independent software vendors to purchase commercial license to embed MySQL into their product. For CIO’s who does not want to make a false move while choosing a product can opt for vendor-specific plug-ins or OpenStack, which offers licensed software for free.

Open Application Programming Interface (API) and Software Development Kit (SDK):

An open SDN solution provides API for programmability, and is intended for the development of SDN applications by the customers and device vendors. API is a set of protocols, routines, and tools for building software applications, while, SDKs are packages of pre-written code. Some of the SDKs are published APIs, available for anyone to write into their own applications. Open APIs are provided by every SDN and SDN controller solution—OpenFlow, OpenDaylight, OpenContrail and Cisco’s onePK. Additionally, it is important to know that anyone can read/write software applications to these APIs, but the proprietary version is dedicated to the vendor’s devices.

Open Hardware:

Open hardware has ‘open’ references for both compute and networking products, in which the design specifications of hardware are licensed, allowing anyone to study, modify, create and distribute. Individuals can add features and fix bugs in the software; they can even update and improve the source code that underlies in the open hardware. Both Copyright Law and Patent Law are applicable to open hardware; Trademark Law is pertinent to branding name and logos of the open hardware.

What to look for in ‘Open SDN’?

Tons of networking vendors out there are stacking OpenDaylight or OpenFlow for their networks, but following the crowd might be a big mistake while looking for Open SDN. The open source software should better serve business—establishing problem-free network, and add value to the growth of enterprise. The evaluation of openness of SDN is a business-critical factor and needs to be assessed on the following:

• It is important to use an open source software and API that are managed and developed by foundations—Linux, Apache and many more.
• Analyze the vendors who contribute the most for open source project ecosystem, this will help CIOs to gain trust on that vendor.
• Probe suppliers (networking or cloud vendors) to participate in a foundation-managed project and open their APIs to foundations for standardization.
• Get confirmation from suppliers about indemnification from threat of lawsuit for writing/adopting an API.
• Encourage companies that control open source projects like VMware to drive projects—Open vSwitch to foundations.

CIO’s Midas touch

Buying a product is a jeopardizing work for enterprise. CIO needs to focus on the benefits that the selected vendor’s product offers as the purchase should be worth a dime. As ROI is constantly weighing on the CIO’s mind, mentioned are some of the benefits Open SDN software possesses:

Reliability: Reliability is one of the important attribute to be considered before investing. As softwares include bugs, these are failures to meet the specifications. On perspective of bugs, severe defects in an open source SDN software can be fixed within no time as the source code are open to developers. After these bugs are fixed by developers, users can get their current version updated by unofficial fix or they can wait for an official fix. Whereas in closed-source software, the users are dependent upon the vendors' internal processes to get update for the bugs.

Stability: Software has been an almighty tool for every business environment which keeps a stable flow of profits into the organization. This is the spot where the software vendors play their turn by persuading their customers for an upgrade. Even open source software is not exempted from upgrades, but prevents daunting of pressures from software vendors.                   

Auditability: While searching for Open Source SDN software, CIOs tend to forget about the software’s auditability. Coming to Closed Source software framework, users envisaging the future changes trust vendors for claims made for different qualities—security, freedom from backdoors, adherence to standards and flexibility. But, as the Closed Source software does not have an open source code and those claims form the users remain incoherent. With ‘Openness’ flourishing in the market, inspection or certification needs from third party auditors for business-critical processes will increase in the near future.       

Cost: When it comes to the costs incurred in a business tool, CIOs should not focus on what is the purchase cost of software, but should check the Total Cost of Ownership (TCO) of the software. An Open Source software offers low TCO by enabling users to upgrade at low fees, and management tool cost. Maintaining is very simple as the Open Source software reduces downtime and data loss. Also the existing hardware life is increased without disrupting performance.  Similarly, in Closed Source software framework the whole proprietary of the software is affiliated to its vendors including the cost of upgrades and maintenance, leaving no option for the users to choose other vendors.    

Flexibility and Freedom: Open source SDN Software will eliminate the dependency of the CIOs to a confined SDN Software Vendor when compared to the Closed Source Vendors. With this freedom an Open Source offers flexibility, as there are many developers out there who provide source code which are available; at architectural level flexibility comes when users leverage trusted standards for interworking.