VoIP Playing Up? Here’s A VoIP Troubleshooting Cheat Sheet

Voice over Internet Protocol (VoIP) is a brilliant piece of technology when it works. It uses an Internet connection to make voice and video calls, eliminating the need for traditional phone systems entirely. The calls are significantly cheaper, there’s no headaches around hardware and with the upcoming 2027 landline switch-off, most businesses have already made the move over to it.

But come the day that your VoIP system starts to misbehave – sometimes when you’re on a call pitching to a client – it can feel like the technology has launched a personal attack on you. Fortunately though, most of these VoIP “gremlins”, we’ll call them, end up being the same problem every time, just wearing a different disguise. The best part is that the majority of them can be sorted out without having to ring the call centre.

The Most Common VoIP Issues (And How To Fix Them)

While it may be tempting to launch the handset across the room in frustration, sometimes you just need to start with the basics. First things first, reboot the system for about thirty seconds. It’s the oldest trick in the book but restarting your router and VoIP phone usually clears out more nonsense than it has any right to.

If that still doesn’t work, here are a few other things you can try.

A Faulty Or Unreliable Internet Connection

VoIP needs the Internet to work so if your connection isn’t 100% stable, chances are your VoIP system will give it away. The best thing to do is run a speed test to check your current situation. A single call is roughly 100 kbps each way which barely slips bandwidth but if your connection is overloaded, it will affect the call instantly.

If you have an important call that needs to happen, sometimes it’s worth ditching the Wi-Fi completely. If you can, plug the phone straight into the router with an ethernet cable. Wireless is convenient but with a time-sensitive call, it’s not always worth the risk.

Choppy Or Distorted Audio

The most common complaint that VoIP users have is when the audio sounds robotic or breaks up entirely. It almost always comes down to your network dropping or delaying your voice that’s being transmitted over the connection. It’s called packet loss and jitter, but you don’t need to get technical to be able to sort it out.

To fix this, you need to give your voice traffic priority over everything else on your network. Modern routers will have a setting called Quality of Service (QoS) in the admin panel. All you need to do is turn it on and set it so that voice comes first and your calls don’t need to fight for bandwidth anymore.

If that doesn’t work, you can ask your service provider to check for packet loss on the line itself. In that case, the “gremlin” isn’t even in your physical location.

Hello? Is Anyone There?

There are very few things that are as maddening as one-way audio. You can hear the other person perfectly, but apparently you’re shouting into the void. Nine times out of ten, this is because your firewall or router is being a tad overprotective and blocking the sound from travelling back the other way.

The usual culprit here is called SIP ALG, a router feature. It’s supposed to help VoIP but ironically, it tends to mangle it instead. Once you switch it off, it should clear up the one-way audio issue. While you’re in there, you can also check your firewall isn’t blocking the ports that your VoIP service needs to work. If you’re uncertain, your provider will be able to help.

Talking To Yourself, On Repeat

That annoying echo, when you hear your own voice bounce back at you a second later, is usually because of the hardware in the room – not the network. It’s often a headset or handset issue, or sometimes the sound leaking out of a speaker and back into a microphone.

What you can do is nudge the volume down a bit if it’s turned all the way up. If one phone in particular always echoes while the others don’t, it may be the culprit and will need to be replaced.

Calls That Keep Dropping

Calls that drop out mid-sentence are their own special kind of frustrating because everything seems fine – until it isn’t. If it’s happening on every call, check your connection stability first. A broadband line that continues to drop will take your calls along with it and it’s on your Internet provider to fix.

If it’s a bit more random, the SIP ALG trick is worth a go here too. It’s fond of cutting calls off at odd intervals every now and then. And if that doesn’t do it, it may be an ageing router problem.

When The Whole System Goes On Strike

Occasionally, the handset might not register at all with no dial tone and an error flashing on the screen. Again, check the basics first, namely your login details. A mistyped password can stop the system dead in its tracks and it’s probably the easiest thing in the world to overlook (we’re only human after all, we do make mistakes).

If you’re certain your credentials are correct, you go straight back into firewall and SIP ALG territory. The same settings that block audio can also stop the phone from checking in with your provider. And if the firmware hasn’t been touched since the year dot, a quick update can iron out any issues as well.