How to Troubleshoot Common VoIP Problems

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There’s no denying that making the switch to cloud communications and VoIP technology in an increasingly virtual working environment is a wise choice. Adopting IP telephony and replacing legacy PBX systems can save money, improve efficiency and productivity, and allow your teams to be significantly more mobile. 

With businesses the world over turning to more virtual, cloud-based systems, focusing on digital transformation means VoIP phone systems are becoming more popular than ever before. 

However, while Voice of IP software offers a huge number of benefits, and facilitates a more efficient remote workforce, it does come with a few pitfalls from time to time. Switching from legacy systems and on-site hardware, to a software alternative means businesses need to get to know a little about how it all works, and how to spot and quickly troubleshoot some of the common VoIP problems as they arise. 

Of course, IT support, and your provider’s customer support team will be on hand to help you out, but for many of the common VoIP issues, this may not be necessary, meaning you can avoid waiting on hold, and wasting your support resource and time. 

We’ve outlined some of the most common issues you might encounter when switching over to a VoIP phone system, giving a breakdown of the most likely causes, and how to fix them as quickly as possible, without the intervention of your IT team. 

Here are some of the most common VoIP problems— with details on how to fix them. Feel free to skip ahead if you need a quick fix for one of the below: 

  • Choppy of broken audio
  • Network issues
  • Echo
  • Jitter
  • Dropped calls
  • A device that doesn’t ring or goes straight to voicemail
  • No sound upon connection
  • Trouble connecting outbound calls
  • Delays with interoffice calls
  • A VoIP phone that doesn’t turn on

Top 10 VoIP Problems and how to fix them

There are a number of common issues that arise for VoIP users time and time again. But the good news is, for the most part, these can be resolved relatively easily and usually without the intervention of the IT support team. We’ve outlined the top 10 most common VoIP problems, why they occur, and tips on how to fix them. 

Choppy or broken audio


Woman receiving a spam caller


Arguably one of the most commonplace issues for VoIP users is choppy or broken audio. Choppy audio, more often than not, is a result of poor bandwidth. 

Solving this seemingly simple issue doesn’t necessarily mean pointing the finger at your internet service provider (ISP). It doesn’t necessarily mean there is too much traffic on the network either, which is a common misconception with this particular issue.

One of the simplest ways to troubleshoot this one is to check the apps you have running. Oftentimes, you might find that you have some app or other running in the background that is eating up all your data, meaning VoIP traffic struggles to take precedence. 

If you’re frequently battling with broken audio, it’s worth taking the following action: 

  • Turning off other devices connected to the network
  • Running a test of your bandwidth speed
  • Check your running applications and their respective bandwidth usage
  • Configure your QoS (Quality of Service) to prioritise VoIP traffic

Network issues

If you’re experiencing general network issues, it can have a huge impact on your productivity and your VoIP calls will suffer the consequences in terms of quality. 

The best way to ensure you can optimise your VoIP performance is to ensure you have the right solutions in place to meet your business’ needs. From the outset, make sure you appoint a reliable, trusted VoIP provider with a 99.99% minimum uptime SLA and check for the following: 

  • Carrier-grade reliability and security 
  • 24/7 monitoring 
  • Tier 1 network centres


Phone echoing can really interrupt your call and affect comprehension especially in video meetings. To keep echoing at bay, there are a number of factors to asses. 

Echoing is most commonly caused by acoustic or electromagnetic interference, or incompatible or faulty hardware. 

Electromagnetic echoing can occur when your hardware is simply too close together, and issues with your hardware can create interference or ‘bounce back’, causing voice packets to seemingly echo and disrupt the conversation. To mitigate echoing, try the following tactics: 

  • Take your device off speakerphone (if applicable)
  • Move your router away from your computer monitor
  • Turn down the volume on your speakers or earpiece to see if this minimises the interference
  • Check your internet speed
  • Disconnect any splitters and caller ID devices that might be connected to your router or phone
  • Update your video conferencing equipment, phone, or headset to ensure the best compatibility with the software


Jitter describes the delayed or misplaced arrival time of voice data packets. Occurring in any VoIP call conversation, jitter can result in snippets of conversation arriving in the wrong order, often with snippets entirely missing which can cause real confusion. It is often caused by the extensive VoIP traffic, with a huge number of different data packets travelling over the same IP network at any given time, causing significant latency.

It’s important to search for VoIP providers that strive to keep delays to under 20 milliseconds. Or another way to overcome issues with jitter, is to use a jitter buffer, which collects the VoIP packets first, then distributes them to the recipient IP address at a steady and even pace. 

Dropped calls 


Confused woman as her call is dropped


Dropped calls; calls that end suddenly, and without warning in the middle of your call are another extremely disruptive, but sadly common, issue when it comes to VoIP communications. Particularly in a professional environment, dropped calls can have a huge impact on productivity, efficiency, and customer satisfaction, so being able to troubleshoot this issue quickly is crucial. 

The first port of call should be to check the compatibility of your VoIP hardware, and check that your conferencing equipment is up to date. It’s worth considering turning on automated updates to make this process easier and check with your service provider that you’re using the most up-to-date version of the software, and that they haven’t set up any automatic disconnection caps after a certain number of connected minutes. It may also be helpful to disconnect, then reconnect the devices connected to your VoIP network to help you isolate and resolve any issues. 

Your VoIP device doesn’t ring or goes straight to voicemail

If you’ve noticed that your missed calls have gone straight to voicemail without ringing out, this can be hugely disruptive, particularly if you conduct a number of calls throughout your working day and frequently need to call clients or colleagues back. 

Whether your calls are going directly to voicemail or being forwarded to another device, missing them means you could be letting the side down in terms of customer satisfaction. 

A commonly cited, and critical issue with VoIP technology, this one is thankfully pretty easy to rectify. 

The first step, before contacting your IT support, should be to check your phone settings as it’s most likely that something simple, such as your forwarding, or even ‘do not disturb’ may have been overlooked. It’s also worth making sure that your phone is still registered with your current VoIP service provider. 

No sound upon connection

Another common VoIP challenge is a lack of sound on connected calls. This can be the case with outbound calls, received calls with only one-way audio, or occasionally for both parties on any given connected call. This frustrating back and forth can be hugely frustrating and can have a major impact on your professional image and productivity. 

In many cases, this issue is caused by your SIP application layer gateway (ALG) , meaning there may be firewalls intervening with your RTP packets. In most cases, adjusting your SIP protocols or disabling SIP ALG will resolve the issue as you’ll be able to reopen the ports and allow voice traffic to flow freely again. 

Issues with making outbound calls 

Another common, and very frustrating issue with VoIP technology is the inability to connect outbound calls. This may present itself by simply not connecting once you’ve dialled the number, or with an ‘x’ on your phone screen or softphone interface. This can be hugely problematic, particularly if you run a business such as a call centre, being able to make outbound calls is non-negotiable and can result in a huge impact on your business continuity and bottom line if the issue persists. 

Again, this could be an issue with your SIP ALG. Often this inability to connect outbound VoIP calls means that SIP ALG and firewalls are disrupting the internal network VoIP traffic, meaning your routers are prevented from processing traffic. If disabling your SIP ALG does not work, then it might be worth considering switching to a VLAN (virtual local area network) 

Delays In Interoffice Calls


Businesswoman yelling at laptop with bullhorn in conference room


If you’re noticing delays in conversations with colleagues from different office locations within your company, this can also be a common VoIP problem. Latency in conversations can be highly disruptive and could cause significant difficulty with internal virtual meetings, conference calls and phone conversations between employees. The cause is a fairly simple one. More often than not, this interoffice call latency is caused by too much traffic on the network.  

It is possible to try to reduce your internal network congestion but putting restrictions in place on peak calling times may not always be possible. It might be worth checking if you’re using terminated cables. If so, the most appropriate solution might be to upgrade your system to a business-class router and ensure that VoIP traffic is set to a higher priority to ensure your internal calls can take place without latency in the future. 

VoIP phone doesn’t turn on

There’s nothing more frustrating than when your phone simply doesn’t turn on. If you have a busy schedule of meetings and a phone that doesn’t work, it can be extremely stressful, and disruptive for you and your staff. 

The good news though, is that this one is fairly easy to troubleshoot and resolve, without having to wait on hold to the support team. The answer is to make sure you use a PoE network switch, or alternatively a plug in your AC adapter, which is usually supplied alongside the phone. 

Best Practices to Avoid VoIP Problems

While VoIP technology on the whole is reliable and facilitates better agility and mobility for your business teams, it requires a little prior knowledge on how to troubleshoot, or simply avoid issues upfront. 

While it’s sensible to rely on your provider’s support team or your in-house IT specialists to help with complex issues, it’s important to set yourself up for success when implementing a new VoIP system. 

Whether you want to adjust your current VoIP solution to help you solve some recurring issues, or you want to facilitate the best possible performance for a newly appointed one, here are some of our best practice tips for smoother business VoIP calls. 

  • Set your QoS (quality of service) to prioritise IP data traffic
    Ensuring that your router and switches are set to favour SIP traffic and devices will mean you allow for better capacity for voice and video calls with less interference.
  • Limit phone calls via WiFi
    Using a dedicated ethernet line could significantly help in allowing for VoIP data packets, leaving WiFi capacity for browsing and other necessary day-to-day usage.
  • Implement a VLAN (virtual local area network)
    Separating your VoIP phones so that they can function within their own VLAN will allow for better overall performance in the long term.
  • Choose a well-respected, reliable provider
    Selecting an established, trusted VoIP provider and working in partnership to align with your business goals is the best way to get the best possible service levels from your communications software.

If you’re thinking about migrating to the cloud or switching your legacy system with a reliable VoIP solution, the best starting point is to choose the best software that will allow for flexibility, and a trusted provider that will support the growth of your business. 

For a more in-depth overview of VoIP technology and how an IP phone system might work for your business, check out our Definitive Guide to a VoIP Phone System.  

Allyn Jayawon


Allyn is the SEO Specialist for EMEA at RingCentral, the leader in cloud communications solutions.

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