How to Solve VoIP Issues and Improve Your Call Quality

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VoIP or Voice over Internet Protocol is a technology that delivers voice communication and multimedia sessions over the Internet. It gives your call center the opportunity to contact with customers across the world. However, it has its flaws as well. What are the most common VoIP issues and how to solve them? Let us try to find out.

How does VoIP work?

When a user is talking via VoIP line, their voice is transformed into a digital stream that is turned into digital data packets. Each of them contains about 20 milliseconds of your voice. These packets are transmitted across the Internet to the device of the person they are talking to. The data are transformed back into an analog stream and the person hears the user’s voice. This process is very quick so we perceive it like an ordinary conversation. But only if there are no quality issues…

Source of the problem: Use our Checklist

The first thing you should do when having a VoIP issue is to find the source of the problem. We have prepared a small checklist for you on this.

  1. How frequently does it happen?
    • The issue is irregular, only with some calls. There can be issues on the callee side (the cell phone is in the bad zone, the carrier used the unstable route, etc.).
    • All calls have the same issue. It is the reason for further investigation.
  1. What is the type of issue?
    • You and the callee couldn’t hear each other. Give your call center software vendor an exact description of such a situation (when and to what phone number you tried to call, attach a call record, too).
    • Only one side can be heard. Contact your system administrator to check the NAT (Network Address Translation) and firewall settings.
    • Audio quality is bad. Check the sound card, microphone, and volume settings. Try to make the call from another computer with another headset.
    • Calls were dropped or there was a long delay between the phrases. In most cases, the main reason is the usage of Wi-Fi connection that is not recommended for VoIP telephony because of its instability. Also, check your router settings and the stability of the Internet connection.

If none of the suggested decisions helped, make the network diagnostics following your vendor’s instructions.

The most common VoIP problems and how to solve them

Problem #1. Jitter

What is jitter? It happens when data packets are delivered late. They don’t move through the network steadily. Data packets take different paths so some of them arrive later than others. You have definitely faced this problem during Zoom or Skype meetings when some of your colleagues started speaking in a metallic voice like a robot. It may sound funny but not when you are listening to customers. How to fix this problem?

The first thing you should do is to check your network. Maybe, this audio issue is caused by the unstable Internet connection (that’s why we recommend you forget about Wi-Fi and use a wired connection for all your agents).

If the network is okay, the next step is to use a jitter buffer. It is an area where data packets are temporarily stored and then sent out at regular intervals. A jitter buffer makes data transmission smoother and ensures reliable call quality.

Problem #2. Latency

Latency is a lag time between a caller speaking into their phone and a callee hearing them. If this time is big, it may cause echoes during the calls. If it is too big, users can speak over each other. Why does it happen?

Latency can be caused by different factors. In many cases, it is network congestion. Yes, your network can have “traffic jams”. When someone is streaming videos or downloading big files during a call it may result in severe latency in a conversation. What’s the solution? To prioritize VoIP traffic. It means using the Quality of Service (QoS) process that we will consider below. It is also important to ensure that your call center is located in a separate subnetwork that can’t be influenced by other departments.

As we’ve already mentioned, a congested network is not the only reason for latency. It may be caused by the wrong codecs - programs that encode audio into digital data packets. If your VoIP app allows you to tweak codecs, you can change them. Otherwise, contact your Internet provider. Another reason is that you use old hardware that doesn’t work well with new networks or new software. And finally, a bad headset can be trouble. That’s why we recommend you to make a thorough infrastructure audit to reveal what the problem is. 

Problem #3. Poor Internet Connection

Use a speed test tool (or several of them to compare results) to check how reliable and quality your Internet connection is. It will show you download and upload speeds, ping and jitter times, and overall capacity. If your connection is unstable despite using Ethernet cables instead of Wi-Fi and a speed test failed the problem may be on your service provider’s side. 

Problem #4. External Network Improperly Configured

Make a network audit to check how your external network is configured. We have already mentioned QoS. This process means that you set up higher bandwidth priority for VoIP packets than for other data. It ensures that your agents won’t have problems during calls if someone tries to stream music or attach a 200 Mb file to e-mail (although we strongly recommend not doing it anyway). In this case, the system will give priority to VoIP traffic. It is especially important when the connection is slow. We recommend reserving at least 50% of the available network bandwidth to accommodate any spike in usage. This number may be different, depending on your industry specifics. Our experts can give you recommendations on how to configure your network properly and create a project of a call center network organization thus making both our outbound and inbound call center software more efficient.

Source: Nehos

Problem #5. Hardware Problems

Hardware may be another reason for VoIP issues. One of the troublemakers is a headset. Some of them might not work well with certain operating systems or disconnect from a softphone if a user is silent for too long. Other headsets can have microphones that pick up incoming audio and cause one-way connection or sound distortion. We recommend using professional-grade USB headsets for your agents and get regular updates for their drivers.

Another troublemaker is VoIP phones. If you use VoIP phones and one of them doesn’t work make sure if its MAC address is registered.

And finally, routers and other network hardware. Use properly selected and configured active network equipment and make correct settings to ensure trouble-free workflow in your call center.


Any technology isn’t perfect. However, the proper use of our recommendations and experience will help you to minimize all the flaws and ensure the high-level performance and customer service in your call center.

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