How do I test bandwidth, latency and jitter for VoIP?

Run a speed test and focus on more than just download speed. A single HD VoIP call typically needs around 100 kbps upload and download. Check that latency is under 150 ms (ideally under 50 ms), jitter is under 30 ms, and packet loss is 0% or as close as possible. Poor results usually indicate an ISP or internal network issue.

How do I enable QoS (Quality of Service) on my router?

Log into your router admin panel and enable QoS or media/voice priority mode if available. Alternatively, manually prioritise VoIP traffic by giving higher priority to UDP ports 5060 (SIP signalling) and 10000–20000 (RTP audio). This ensures voice traffic is prioritised over other network activity.

Should I use a wired connection for VoIP calls?

Yes, whenever possible. Wi-Fi can introduce variable latency and interference, which affects call quality. Use Ethernet for IP desk phones or laptops during calls. If Wi-Fi must be used, prefer a 5 GHz network and stay close to the access point for stability.

How can I reduce competing network traffic during VoIP calls?

Large downloads, cloud backups and streaming can consume bandwidth and degrade call quality. Schedule heavy tasks outside business hours, limit streaming during peak call times, and consider upgrading to a dedicated leased line if your organisation has high call traffic demands.

What codec settings should I use for VoIP?

Codecs affect how audio is compressed. G.711 provides the highest quality but uses more bandwidth, while G.729 uses less bandwidth but may introduce audio artefacts. For most fibre broadband connections, G.711 is recommended if bandwidth allows it.

Do I need to upgrade hardware for better VoIP call quality?

Yes, in some cases outdated hardware can significantly impact call quality. Using modern IP desk phones or a high-quality USB headset with noise cancellation and echo suppression improves performance compared to built-in laptop microphones or older devices.

Why Is My VoIP Call Quality Poor — and How Do I Fix It?

Q: Why is my VoIP call quality poor — and how do I fix it?

Poor VoIP call quality — choppy audio, echo, dropped calls or robotic voices — is almost always fixable. It typically comes down to four main causes: insufficient bandwidth, network congestion, misconfigured settings or inadequate hardware. Diagnosing each of these areas usually resolves the issue.

About the Author

More About Kully

Poor VoIP call quality, choppy audio, echo, dropped calls or robotic voices are almost always fixable. It comes down to one of four culprits: insufficient bandwidth, network congestion, misconfigured settings or inadequate hardware. Here's how to diagnose and resolve each one.

At The VoIP Shop, our UK-based technical support team troubleshoots these issues every day for businesses across the country. These are the exact steps our engineers take.

1. Test Your Bandwidth, Latency and Jitter

A single HD VoIP call needs only around 100 kbps upload and download; raw speed isn't the issue for most businesses. What kills call quality is latency (delay) and jitter (inconsistent delay). Run a speed test and look for:

Latency: under 150 ms (ideally under 50 ms)
Jitter: under 30 ms
Packet loss: 0%, or as close as possible

If your figures are worse than these, the problem lies with your ISP connection or internal network, not the VoIP platform itself. For delay specifically, see our guide on how to reduce VoIP latency.

2. Enable QoS (Quality of Service) on Your Router

QoS tells your router to treat voice packets as the highest priority on your network, so a large download or video stream doesn't steal bandwidth mid-call. Log into your router admin panel and:

Enable a VoIP or media priority mode if available
Or manually prioritise UDP ports 5060 (SIP signalling) and 10000–20000 (RTP audio)

Our cloud phone systems are preconfigured to work with QoS-enabled routers, and our engineers can advise on the right settings for your hardware.

3. Use a Wired Connection

Wi-Fi introduces variable latency and radio interference, both enemies of consistent call quality. Wherever possible:

Connect IP desk phones directly to the router or switch via Ethernet
If using a softphone on a laptop, use a wired connection during calls

If Wi-Fi is unavoidable, use the 5 GHz band and reduce the distance to the access point.

4. Reduce Competing Network Traffic

Cloud backups, software updates and video streaming all compete for the same bandwidth. Practical steps:

Schedule large backups and updates outside business hours
Limit streaming during high-call-volume periods
Consider a dedicated leased line if your business carries heavy call traffic

5. Check Your Codec Settings

Codecs determine how audio is compressed for transmission. G.711 delivers the best quality but uses the most bandwidth; G.729 uses less bandwidth but can introduce artefacts. For most UK businesses on fibre broadband, G.711 is the right choice. If your provider's portal allows codec selection, match it to your available bandwidth.

6. Upgrade Your Hardware

Outdated or low-quality hardware causes more call-quality issues than most businesses realise. We supply and preconfigure Yealink, Cisco and Poly IP desk phones, tested to work with our cloud platform. If you're using a softphone on a computer, a USB headset with noise cancellation and echo suppression performs far better than a laptop's built-in microphone.

Still Having Issues?

Our UK-based engineers can remotely diagnose and resolve call-quality issues on systems we support.

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Written By | About the Author

Kully Hothi

Sales Director

More About Kully

Kully has over 15 years of experience in the VoIP and telecoms industry. Drawing on a background in telecoms sales and leadership, he provides expert, impartial advice on VoIP and cloud telephony solutions. As a lead author for The VoIP Shop, Kully helps businesses understand and adopt modern communication technologies