8 Most Common VoIP Problems and How to Fix Them
By Natália Mrázová
| 11. November 2021 |
Phone systemVoiP
By N. MrázováNatália Mrázová
| 11 Nov 2021 |
Phone systemVoiP
    By N. MrázováNatália Mrázová
    | 11 Nov 2021
    Phone systemVoiP

    8 Most Common VoIP Problems and How to Fix Them

    most common VOIP problems

    VoIP systems offer countless advantages, compared to traditional hardware call center solutions. It significantly reduces costs, offers advanced features, and allows you to work from anywhere you want. Yet, nothing is without flaws. VoIP also has its disadvantages.

    In this blog, we will look into the most common problems, discuss how to troubleshoot them, and suggest what to look for in a truly quality VoIP provider. 

    How Does VoIP Work? 

    A shortcut VoIP stands for Voice over Internet Protocol and is also known as Voice over IP.

    This technology allows you to transmit voice calls over the internet which replaces the traditional phone networks. The VoIP system converts analog signals (voice) into digital one. When you start the phone call, all data is broken into small chunks. It’s called voice packets. The packets are individually routed on different routes within milliseconds, which makes the data transfer as efficient as possible. Once all the data packets arrive at their final destination, they are put back together.

    Most Common VoIP Problems and Their Solutions

    Now, let’s take a look at 8 most common VoIP issues and how to troubleshoot them.

    #1 Echo on VoIP Calls

    Echo on VoIP calls is also known as latency. Voice packets arrive at different time intervals and sound levels, which makes it challenging to lead a productive conversation. 

    It’s common that a caller isn’t fully aware of the echo, since only a call receiver hears most of it. 

    There may be three potential causes of echo interference: The device, bluetooth headset lag or network latency.

    A guide to the most useful call center features

    How to Troubleshoot:

    • The Device

    First, you need to find the cause. Examine the device you are using for VoIP calls. Is the system updated to the latest version? Don’t forget to also check hardware, if everything is plugged properly or there isn’t any damage. After you take a careful look, perform a test of the functionality. It may allow buffers, regions of memory storage that temporarily stores data, to empty and re-synchronize with the VoIP service. 

    • Bluetooth Headset Lag

    If the device configuration is not a cause, chances are that the problem lies in your bluetooth headset. If you notice the delays in your bluetooth headset but not the corded handset, it’s possible to fix it in quite a short time. 

    You usually notice echo on VoIP calls in the earpiece and mouthpiece of your phone or headset. That is because the earpiece volume is too loud which overpowers the mouthpiece. Try to cover your phone’s mouthpiece. If echo gets lower, you only need to turn down the volume of the earpiece. 

    Another cause of the echo effect may be a faulty internet connection. Try to improve your network stability. Run a speed test to find out if your level of bandwidth space is sufficient. 

    Next possible cause: congestion. A reduced quality of service that occurs when a network carries more data than it can handle. If this is the case, examine your Quality of Service (QoS) configuration on all network links. 

    You may also search for excessively large jitter buffers and eliminate them. Jitter Buffers can normally cause minor sound delays. Yet larger they are, larger is the sound delay.

    If nothing of the above mentioned helps, the issue may lie in a VoIP itself. Consider choosing a more reliable provider. We guarantee crystal clear audio under any circumstances.

    #2 Jitter 

    If parts of your conversation are missing, jumbled or out of order, you are experiencing a Jitter. It can make important parts of your conversation impossible to understand which doesn’t help to raise customer satisfaction. 

    Jitter happens while millions of data packets travel simultaneously over the same IP address. Jitter buffers should collect the packets first and send them to the receiver at a steady pace. That assures clear conversation. But sometimes, they can be configured in the wrong way, causing some data packets to arrive either too soon or too late – in irregular intervals. 

    If the buffer is too small, you’ll experience gaps in conversation. On the contrary, if it’s too big, you are going to experience increased delays in voice delivery. The buffer has to be just right. 

    infographics 8 common VoIP problems

    How to Troubleshoot:

    First, we recommend you to contact your network administrator and ask him to do reconfiguration based on your specific issue.

    Another solution, the most common one, is to upgrade your internet connectivity through ISP (Internet Service Provider). It is possible that your internet doesn’t have enough bandwidth to power all of your devices. Try speed test checkers. If it shows more than 20 ms, it means your issue lies in ISP. You may consider finding different one

    Another possible cause is Wi-Fi. It’s certainly not the best solution for VoIP calls. Consider another type of internet connection. Switching to Ethernet is a good choice, though even that step may have its flaws, such as faulty Ethernet codesOutdated modems can also be a reason for jitter. 

    #3 Dropped Calls 

    This issue is extremely problematic because your client may think that you just hang up on him. Dropped calls occur during packet loss – some packets do not arrive at their final destination. For correct data transmission, you need all of them. Even one missing piece may cause all packets to be lost. 

    Mostly, dropped calls occur during high volume of outbound calls. You may also notice that drops happen after a fixed amount of time

    How to Troubleshoot:

    First, you want to try disconnecting all devices that are connected to VoIP networks and reconnect them one by one. This way, you can determine which one is causing the issue. 

    The core of the problem may also lie in the firmware of your device. Make sure that all of your software, VoIP hardware and equipment are up-to-date. Turning on auto updates may be a good idea. 

    A cause may also lie in UDP (User Datagram Protocol). The role of UDP is to provide a mechanism that detects corrupted data in packets. Yet, due to lack of error checking features, it can experience timeout – an extended amount of time a UDP route stays open on a firewall or router.

    Try to incorporate TCP (Transmission Control Protocol) that has an error checking feature incorporated. It suspects when the firewall may close the connection and consequently prevent it from ending the call.

    The problem can further be on the side of a provider. Contact the provider to check if the issue does not lie in your settings. You might have a set-up that automatically disconnects the call after a specific amount of time, to ensure these are not invalid open calls. 

    #4 Unable to Make Calls

    Dropped calls are annoying, yet sometimes it may happen that the VoIP platform does not allow you to make outbound calls at all. This is either by completely failing to connect or by displaying an X on the screen. 

    How to Troubleshoot:

    First possibility: The caller ID is banned. Check it with your provider or buy a new virtual number. We will get to this in a specific paragraph. 

    It’s also possible that you have two routers connected which drop critical data packets. This has less in common with router configuration and more with network layout. Two routers simply cannot process and transmit packets because of firewalls that disrupt internal network and VoIP traffic. 

    Some protocols are processed by ALG (Application Layer Gateway) and rewritten by firewall or NAT (Network Address Translation) for a better flow. This may cause several VoIP problems. As a solution, disable SIP ALG (Session Initiation Protocol Application-Level Gateway) and make sure you don’t have double NAT or two routers inhibiting pocket flow. 

    Another way can be to place VoIP phones on VLAN (Virtual Local Area Network)

    #5 Missed Calls

    Echos, disruptions, dropped calls – these are all harmful for your customer relationship. But what if the call doesn’t ring at all or it is automatically transferred to another device?  This for sure doesn’t play well for your reputation and revenue. 

    How to Troubleshoot:

    Good news, this problem can be fixed pretty easily. There are three possibilities. 

    First – your phone is no longer registered with the VoIP provider. It is enough to simply contact the company and ask for help on how to register your device again. 

    Second possibility lies in settings. Check if your phone isn’t in Do Not Disturb (DND) mode. Also revise your call forwarding settings. It might happen that you adjusted your call forwarding configuration and forgot to reset it back to standard settings. 

    #6 Calling System Doesn’t run

    Another VoIP problem is that your calling system simply cannot be turned on, or one system doesn’t work while others do

    How to Troubleshoot:

    • Your calling system wouldn’t turn on: 

    In this scenario, it is possible that you are not using a PoE (Power over Ethernet) connection. PoE requires quality wiring and proper network switch. The solution is, again, pretty simple. Just use a PoE network switch or plug in the AC adapter. Network administrator shows that T568-B wiring pattern is preferred.

    • One callings system doesn’t work while others do:

    Try to use a functioning and malfunctioning system in the same known working spot, using the same network port. If the situation remains the same – one device works but other doesn’t – the problem will lie in the device. 

    If both calling systems work, it can mean that an Ethernet drop is not working. You may also update your configuration and firmware. Try to call your VoIP provider if there are any available updates. If not, you will very probably need to replace the non-functional device. 

    #7 High Voice Compression

    Next disadvantage of VoIP you may experience is a problem with Voice Compression. VoIP systems work with various codecs to compress the audio while traveling through the internet. Each one is different and has its own oddities. 

    How to Troubleshoot:

    There are two types of codecs for voice compression – G.729 and G.711. In the case of the first one, codec G.729, the audio compression is higher, therefore the quality gets worse. On the other hand, the G.711 has lower compression, thus better voice quality. For truly premium calls, contact telecom suppliers that deal with G.711 codec. Keeping up with the latest telecom trends such as advancements in codecs and compression technologies is essential for businesses seeking high-quality voice communication.

    For successful codecs transfer, a VoIP provider needs to have an enterprise-grade bandwidth, too. 

    #8 Problems with Caller ID

    Reaching customers and being reached by customers is the primary aid for each sales and customer support department. Therefore, it’s not an ideal situation when you may not be able to call them.  It can be caused by an issue with Caller ID – a service that transmits a caller’s phone number to the recipient’s phone equipment.

    How to Troubleshoot:

    • Local Caller ID

    First reason can be a local caller ID. This problem is most commonly connected with landline calls. Many countries do not allow using a local Caller ID for international companies, placed outside of a given state. 

    • Caller ID is banned or hidden

    There is also a possibility that the Caller ID is banned or hidden. Some companies want to call anonymously, therefore they hide their Caller ID. Yet that’s not the smartest decision to make. In some countries, it is prohibited on a government level, so you will not be able to call such a number.

    What to Look For In a VoIP Provider

    If your business stands on communication, it is crucial to choose the best VoIP provider possible. First, ask yourself what are your current needs and requirements and how these may change overtime. Then, keep an eye on these criteria:

    International Calling

    VoIP systems are incredibly affordable solutions for long-distance calling. Check if countries where you wish to call are a part of the VoIP provider offer. 

    For example, in CloudTalk, we offer international numbers for more than 140 countries. Using a local phone number from abroad allows customers to call at standard local rates, free of charge. 

    Local phone numbers also increase trust of your customers, since people are often sceptical towards calls from different countries. 

    Third-party Integrations

    One of main advantages of a good VoIP system is an ability to integrate your telephony with other systems. Thanks to integrating your VoIP number with reliable platforms such as HubSpotSalesforce or Pipedrive, you don’t have to manually rewrite data that you already have from one platform to another. This leaves you more time for important tasks, such as building customer relationships.

    Call Management Software (CMS)

    CMS allows managers to follow and lead their teams towards the best performance. They can also predict call volumes or view data such as average pick-up time or average call length. Search for VoIP providers that allow you to follow team performance in a real time. Choose the one offering features like call statisticscall monitoring or real-time dashboard.

    You might also need call queuing services which distribute calls based on specific criteria. In CloudTalk, we offer Automatic Call Distribution (ACD)skill-based routingcall forwarding and more. 

    Customer Service

    Even your customer service may seek customer service. If you need consultancy in any VoIP problem, you might appreciate reaching your provider anytime, ideally 24/7. Choose the one that has a fast way of communication, for example via live chat. 


    This is probably the most important criteria. By a security breach, you risk losing sensitive data, including personal information about your clients. 

    With CloudTalk, your services are always safe. All of them are stored in a modern data center that is monitored 24/7. Our software is in compliance with ISO 27001:2013 security certification


    Budget is a concern of each business, that is unquestionable. VoIP telephony systems can significantly reduce your costs, compared to traditional hardware systems. VoIP providers often have several package options. Consider which one is the most suitable for your needs. 

    At some providers, you can test the services free of charge, for a limited amount of time.