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JA2. Software Defined Networking (SDN) as a Network Traffic Engineering Technique

Statement

As a network engineer, you have just been assigned the task of managing a new Data Centre for a client. Your senior colleague has advised the use of Software Defined Networking (SDN) as a suitable technique for network traffic engineering at this site due to its numerous advantages. Before you start managing the client’s new Data Centre, your senior colleague wants you to do some research.

  • You are to briefly describe the use of Software Defined Networking (SDN) as a network traffic engineering technique with the merits and possible drawbacks of this technique.

Answer

In the era of traditional networking (during the 1990s), network configurations were embedded in the hardware, any changes to the network required physical access to the target device and re-program it with the new configuration; this involves some downtime and disturbance to the service (Angelo, 2019). The invention of virtual circuits allowed for configuration to be stored on software and can be changed by sending conventional commands to the target device, thus devices can be configured while the network is still running. This was a huge breakthrough in networking, but it was not enough to meet the demands of the modern era so it was matured into Software Defined Networking (SDN).

Traffic engineering is a process that allows for controlling the flow of traffic in a network to achieve certain goals, such as load balancing, reducing congestion, improving network performance, and real-time response to other network problems (Swyx, 2020b).

SDN is a network architecture that allows for the centralized control of the network; a dedicated machine that includes software that is responsible for controlling all links (routers, switches, etc.) in the network. This allows us to achieve traffic engineering or management through software.

SDN today has 4D planes, after adopting the OpenFlow protocol in 2008 which regulates the commands that are sent to the network devices. The 4D planes are:

  • Decision Plane: where the control plane makes decisions about how to handle traffic.
  • Dissemination Plane: where the control plane sends decisions to the data plane.
  • Discovery Plane: where the control plane learns about the network topology and the state of the network.
  • Data Plane: where the data is forwarded according to the decisions made by the control plane.

Advantages of SDN include:

  • Centralized control allows for all devices on the network to be managed from a single point at once.
  • SDN can be applied to any network size, from home networks to large data centers.
  • The adoption of the OpenFlow protocol allows for controlling devices from different vendors, types, functions, and capabilities.
  • The central controller can utilize machine learning to automatically adjust and optimize the network depending on the current traffic state.
  • SDN reduced the costs of maintaining, managing, and scaling networks.

Disadvantages of SDN include (JavaPoint, 2021):

  • The SDN architecture is complex and requires a high level of expertise to manage.
  • All links in the network depend on the central controller, if the controller fails, the network may not work as expected or even go down.
  • SDN is not compatible with old network devices, so it may be a hassle to upgrade the network to SDN.
  • The links themselves now accept commands through the network, which may be vulnerable to attacks.
  • The centralized control system introduces more latency to get, interpret, and apply commands which may degrade the performance compared to traditional networks.

To conclude, the use of SDN as a network traffic engineering technique is a smart solution, it allows for a lot of things that were not possible with traditional networking, but it has its drawbacks. Personally, I can not imagine a world where you can not create virtual networks on the cloud, with complete control over all of its aspects, and the ability to change it on the fly.

References