SDN Applications: VoIP Edition

SDN Applications

In a previous article, our writers dived into the software defined networking (SDN) world and explored how it reshaped the Telecoms industry. Simply put, SDN allows operators to modify one or more devices through software instead of accessing a router or switch command line to enter traditional Cisco IOS commands. This innovation then played a crucial role in creating software defined mobile networks (SDMN) for the telecoms industry. SDN applications are numerous and versatile in the industry, notably in IP telephony, also referred to as Voice Over Internet Protocol (VoIP). This area in the sector pertains to a phone system that uses an internet connection to make and receives.

Telecom Freedom in the Cloud

The advancements made in Cloud computing have been exciting and very useful. As a result of its incorporation into the telecom industry, phone services are now free from space, hardware, and software limitations.

The same IP networks that carry basic Internet traffic, including email, chats, videos, social networking data, and much more, can now carry voice and telephone switch data. As a result, VoIP technology is the backbone of cloud phone services. Operators can now use an IP phone or softphone software program to make phone calls, and the software transmitts audio and phone signaling data over an existing network. Therfore, the use of these phone services doesn’t require any specialized equipment or infrastructure.


  • Lower costs: Appropriately integrating VoIP phone systems will decrease phone expenses in most companies. For example, there is no need to purchase extra hardware (i.e., landline phones) as broadband connection powers these networks.
  • Increased accessibility: Cloud-based VoIP service enables accessibility as it allows users to make calls from anywhere. Remote accessibility empowers a business to be adaptable to an increasingly mobile workforce. Mobile workers can continue to be productive no matter where they are.
  • Complete portability: A virtual number, also called a VoIP number, is transferable. This quality implies that you can use the same number everywhere. For those who travel frequently, this news should be especially welcome. If your company relocates, you can keep the same VoIP number.
  • Higher scalability: VoIP is a flexible technology as it expands alongside your business with a minimum increase in expenses.
  • Advanced features for small and large teams: VoIP has auto attendant and call transferring features that give the illusion that an operation is more significant than it is. Similarly, a larger enterprise comes off as approachable.
  • Clearer voice quality: Voice quality should be fine if your Internet connection is quick and reliable. VoIP calls frequently have low latency, no lag, and no call dropouts.
  • Supports multitasking: An attractive feature of this technology is the ability to send documents, images, and videos while on a live call.
  • More flexibility with softphones: These are not hardware devices but programs installed on a computer or other intelligent devices. A good example is Skype.


  • Reliable Internet Connection Required: The service is only as good as the internet connection. It doesn’t use as much bandwidth, but the device needs low receive low latency from the network.
  • Latency and Jitter: When these data packets experience transmission delays or are incorrectly reassembled, latency and jitter occur. These problems might not even be with your network because the main internet backbones alter data routes to deliver traffic in the most dependable, efficient manner.
  • No location tracking for emergency calls

SDN Applications for VoIP

The primary benefit of SDN applications in VoIP is the efficient deployment of quality of service (QoS) mechanisms. QoS deployment is challenging for a plethora of reasons:

  • Extensive person-hours to configure every device with QoS.
  • Any mistake results in significant damage.
  • All devices and networks must use consistent QoS configurations.

Furthermore, it can be tough to troubleshoot network issues or voice quality problems in such a deployment because even a device that is improperly configured could cause havoc on voice packets traveling through that specific network area.

SDN to the Rescue

SDN applications are meant to resolve the challenges in the QoS deployment as they can:

  • Harmonize the policies across all network devices, ensuring end-to-end QoS for all prioritized packets
  • Interpret higher-level QoS requirements and translate them into appropriate configurations that are automatically pushed out to network devices and applied immediately
  • Allow hundreds or even thousands of configuration steps to be applied simultaneously on the whole network, thereby minimizing downtime and person-hours spent and maximizing network efficiency.
  • Detect the location of faults or failures and either indicate them to administrators or proactively adjust configurations to resolve the issues

In addition to these advantages, SDN is always responsive and network aware. The SDN intelligence can adjust dynamically to QoS to ensure the smooth flow of voice and video traffic if changes occur on the network, whether due to hardware failure, hacker attacks, or even legitimate fluctuations in traffic patterns.

SDN Applications for VoIP Deployments


VoIP uses RTP to carry the voice packets and the SIP protocol for signaling. The initial INVITE SIP message sent from the calling to the called device can be detected by SDN applications. The application can actively push flows to create a path for the RTP stream after receiving a copy of this SIP traffic. A bandwidth requirement estimate guarantees an acceptable level of service, and a reservation of the necessary bandwidth starts.

Minimizing Latency

VoIP and video applications must have low latency, especially on networks that span an entire continent or country. Network management can be coordinated to keep this latency to an absolute minimum.

Smarter Bandwidth Usage

The system has enough knowledge to intelligently and dynamically adjust routing and switching parameters across the network, resulting in more effective bandwidth usage and more efficient use of bandwidth-demanding applications like HD and 4K videoconferencing.

Final Thoughts

SDN applications are far and wide. An application was in VoIP. It managed to help overcome the challenges in QoS deployment by harmonizing the policies, interpreting higher-level requirements, allowing a high number of configuration steps to co-occur, and detecting faults. What was once taxing on the network is now manageable.

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