How to set up and configure QoS (Quality of Service) on your business router to prioritise critical traffic

Summary

This guide helps you troubleshoot and resolve: How to set up and configure QoS (Quality of Service) on your business router to prioritise critical traffic. Follow the steps below to fix the issue.

Common Causes

Quality of Service (QoS) is a router feature that lets you decide which types of network traffic get priority over others. For businesses, this is essential when voice calls, video conferences, and cloud applications are competing with background traffic like software updates, file backups, or staff streaming music. By configuring QoS correctly, you can keep your critical communications smooth even when your internet link is under heavy load.

This guide walks you through the general process of setting up QoS on a typical business router. The exact menu names will vary slightly between manufacturers (such as UniFi, MikroTik, Meraki, or Netgate), but the underlying concepts are the same.

Before You Begin

Before making changes, gather the following information:

• Your internet connection speed (both download and upload, in Mbps). Run a speed test during business hours to get a realistic figure.
• The bandwidth requirements of your critical applications. As a rule of thumb, a VoIP call needs roughly 100 kbps per direction, and an HD video conference needs around 2–4 Mbps per participant.
• Your router's admin login and the IP address used to reach its management interface (commonly 192.168.1.1, 192.168.0.1, or 10.0.0.1).
• A list of devices or services you want to prioritise, such as your VoIP handsets, conferencing PCs, or specific cloud platforms.

Quick Fix Steps

1. Log into your router's admin interface via a web browser.
2. Locate the QoS or Traffic Management section.
3. Enable QoS and enter your measured upload and download speeds.
4. Create traffic classes for VoIP, video conferencing, and business cloud apps.
5. Assign higher priority (or guaranteed bandwidth) to those classes.
6. Save the configuration and test with a real call or meeting.

Detailed Instructions

Step 1: Access the Router Management Interface

1. Connect a computer to the router using an Ethernet cable for the most reliable access.
2. Open a web browser and type the router's IP address into the address bar.
3. Enter your admin username and password. If you have not changed these, the defaults are usually printed on the device label.

Step 2: Enable QoS and Set Bandwidth Limits

1. Navigate to the QoS, Traffic Shaping, or Bandwidth Management menu. On UniFi equipment this is under Settings > Networks > WAN; on MikroTik it is under Queue Tree or Simple Queues.
2. Switch the feature on.
3. Enter your measured upload and download speeds. Set these to roughly 85–90% of your actual line speed to leave headroom for overhead and burst traffic.

Step 3: Identify and Group Critical Traffic

QoS works by classifying packets and applying rules to each class. There are several ways to identify traffic:

• By service or protocol: VoIP traffic commonly uses SIP and RTP on UDP ports 5060 and 10000–20000. Video conferencing platforms use specific port ranges or DSCP markings.
• By device IP or MAC address: Useful for prioritising a specific VoIP handset or executive laptop.
• By destination: You can prioritise traffic heading to specific cloud services such as Microsoft 365, AWS, or your hosted PBX provider.

Create at least three traffic classes:

• Real-time (highest priority): VoIP calls and live video conferencing.
• Business applications (medium priority): Cloud platforms, remote desktop, CRM, and email.
• Best effort (lowest priority): Web browsing, social media, and large downloads.

Step 4: Assign Priority and Bandwidth

1. For each class, assign a priority level. Most routers use a scale where a lower number means higher priority (for example, 1 is highest, 7 is lowest).
2. Where supported, set a guaranteed minimum bandwidth for your real-time and business classes so they always receive capacity even when the link is saturated.
3. Optionally set a maximum bandwidth for lower-priority classes to prevent them from consuming the link during business hours.

Step 5: Apply and Test

1. Click Save or Apply to push the configuration to the router.
2. Reboot the router if prompted.
3. Run a VoIP or video call while a colleague performs a heavy download. The call should remain clear and stable.
4. Check the router's QoS statistics or graphs to confirm traffic is being classified and shaped as expected.

Troubleshooting

QoS Does Not Seem to Make a Difference

• Confirm the upload and download speeds entered in the QoS settings match your actual link speed. An incorrect value can render the rules ineffective.
• Verify that traffic classification is matching the correct packets. Use the router's traffic analyser or live graph to see which class your test traffic is landing in.
• Check that the device generating the traffic is using the router as its default gateway and is not bypassing it via a separate modem or mobile hotspot.

VoIP Calls Still Sound Poor

• Ensure SIP and RTP ports are correctly identified in your traffic class. Missing the RTP range is a common cause of one-way or choppy audio.
• Check for double NAT. If your ISP modem is also routing, place it in bridge mode or move QoS to the device performing NAT.
• Test with a wired connection on the VoIP handset to rule out Wi-Fi interference.

Cloud Applications Feel Slow

• Many cloud providers use a large range of IP addresses that change frequently. Prioritising by destination IP can be difficult; consider using the provider's published domain or URL list and applying DNS-based or application-based rules where supported.
• Confirm your upload bandwidth is sufficient. Cloud sync tools are often upload-heavy and will starve other services if the upstream link is small.

Related Articles

• How to configure VLANs on your business router
• How to set up a VPN for remote workers
• Understanding network bandwidth requirements

If you need assistance configuring QoS on your specific router model or want a managed solution tailored to your business, contact your IT support team for further help.

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