VoIP Quality of Service: The Key to Clear, Reliable Calls

What is VoIP?

VoIP (Voice over Internet Protocol) has become an essential component of almost all businesses today. Many organizations choose to utilize VoIP due to significantly lower costs in comparison to traditional PBX landlines. There are also opportunities to avail of numerous features including advanced call routing, integration with CRMs and on-hold messaging. VoIP is not only lower cost but is commonly much easier to scale than traditional infrastructure.

However, VoIP comes with its own set of unique challenges that can occur regardless of your connection speed. These may include limited bandwidth and network congestion issues which can greatly affect your calls, leading to misunderstandings, poor reputation, low productivity, and frustration for both your employees and customers.

What is QoS?

If your VoIP calls are competing with other users, calls may stall, voice quality may degrade or they could be impacted by jitter and echo. For any business, these are significant issues because they interfere with your ability to offer uninterrupted and good quality service. If you are not using a Quality of Service (QoS) policy, it is likely that your VoIP calls are not functioning at their optimum.

QoS for VoIP is a common method of working to remove these problems and optimize your bandwidth to improve call quality. QoS works by prioritizing the network traffic and boosts the clarity and reliability of your calls.

With VoIP, voice protocols are converted into data packets and transferred between users. Routers typically operate on a First-In First-Out (FIFO) model with data packets. But VoIP relies on a call’s packets arriving in the correct order at the required destination. This means that if your bandwidth usage is too high, queuing issues can occur. ‘Packet loss’ can also occur when one or more data packets fail to reach their destination. This is typically caused by errors in data transmission or network congestion.

QoS establishes dedicated network resources based on the type of traffic or the device type in use. It is a way to help enhance your voice quality and ensure the best customer experience. When VoIP issues are severe, one or more users could cut out of the call causing it to drop. Techradar suggests when it comes to voice and video calls, a packet loss of just 0.5% is noticeable and anything above 2% has the potential to damage the conversation.

Setting up your QoS policy

It’s important to remember that setting up QoS for your VoIP system will require some experimentation and trial before you get it correct. For example, through setting priorities, you may slow down other activities on your network such as video streaming. Because of this, it’s recommended you announce the change to employees or anyone else who may be impacted, especially during the experimentation phase. However, a slight delay in the loading time of a training course an employee is undertaking is likely to be worth it, if it means a paying customer has a more positive experience.

VoIP QoS plans how much bandwidth is needed for a certain type of traffic or device through spreading out the available bandwidth across applications. This ensures the most important traffic gets priority and is not negatively affected.

When setting up your VoIP QoS, it is best practice to do the following:

1. Prioritize VoIP traffic: Ensure smooth and uninterrupted communication by giving precedence to VoIP packets above other network traffic. This minimizes audio delays and maintains clear voice quality.

2. Allocate sufficient bandwidth: Assign an appropriate amount of bandwidth to accommodate expected call volumes without congestion or compromising on the quality of the call. It’s also important to consider factors such as the number of simultaneous calls and the bandwidth requirements of each call.

3. Classify VoIP traffic: Accurately identify and prioritize VoIP packets by implementing traffic classification techniques, such as protocol-based or port-based classification. This ensures the consistent and reliable delivery of VoIP traffic.

4. Configure QoS parameters: Optimize QoS settings by configuring parameters like priority queuing, traffic shaping, or bandwidth reservation. These settings prioritize VoIP traffic and ensure its efficient transmission across the network.

5. Continuously monitor your infrastructure from external and internal perspectives, including audio quality: You must continuously monitor key metrics such as latency, jitter, packet loss, and audio quality to maintain high-quality calls. Latency, which measures the delay between the speaker and receiver, should not exceed 150 milliseconds (ms) to avoid noticeable delays. Jitter, the variation in packet delay, should be kept below 30 ms to prevent missed calls or distorted audio caused by out-of-order packet arrival. Additionally, addressing packet loss, where the number of lost packets exceeds 2%, is crucial as it significantly reduces audio quality. By proactively monitoring and optimizing network performance, including audio quality testing, you can ensure clear and uninterrupted voice communications for a superior calling experience.


If VoIP calls are an essential part of your business, you should always have a QoS policy in place. Not only does monitoring VoIP QoS lead to better productivity, it also leads to improved call quality and enhanced customer experience. Without one, your voice quality is likely to suffer and be less reliable, negatively impacting your customers and employees. Monitoring and maintaining a QoS policy is a relatively easy and straightforward way of ensuring the best VoIP call quality for your organization.

About Cyara

Cyara revolutionizes the way businesses transform and optimize their customer experiences. Cyara’s AI-based CX Transformation Platform empowers enterprises to deliver flawless interactions across voice, video, digital, and chatbot experiences. With Cyara, businesses improve customer journeys through continuous innovation while reducing cost and minimizing risk. With a 96% customer retention rate and world-class Net Promoter Score (NPS), today’s leading global brands trust Cyara every day to deliver customer smiles at scale.

To learn more, visit cyara.com or call 1-888-GO-CYARA.

We think you’ll like these too...


Intelligent Use of Alerts in Proactive Number Testing

Alerts allow you to take immediate action to resolve problems, ensure compliance, and maintain good customer service. They save you time and energy by automatically delivering notifications to you.

Read More

The Critical Role of Outbound Testing in Call Centre Solutions

If you are providing Contact Centre Solutions you need to have a way of monitoring your network and your partners’ performance to ensure the operability …

Read More

Why Call Quality Matters: Ensuring Clear Communication

Do you ever find yourself struggling to hear clearly during important business calls? If so, you’re not alone! Let me share the most common reasons …

Read More

Minimize contact center issues by increasing your visibility with proactive monitoring

Contact centers typically aim to handle as many calls as possible and resolve customer issues quickly while maintaining high customer experience (CX) standards. The contact …

Read More

Not Ready Yet?

Subscribe for updates