UK offices rely on Microsoft Teams, 3CX, Zoom and VoIP to keep staff and customers connected. But without Quality of Service (QoS), calls can break up due to guest Wi-Fi, large downloads or VPN traffic. This guide explains how to apply DSCP tagging, WAN queueing and VLAN shaping so every call is crystal clear.
Key takeaways
- Enable DSCP EF tagging on Teams, 3CX and SIP devices; trust and preserve tags across your switches and routers.
- Apply WAN queueing and traffic shaping to prioritise voice/video over bulk downloads.
- Segment guest Wi-Fi with VLANs and rate-limits to protect corporate and voice traffic.
- Monitor jitter, packet loss and MOS with alerts and reports for proactive troubleshooting.
Why QoS matters in UK offices
Without QoS, VoIP calls compete with cloud backups, Teams screen shares and guest devices. UK SMEs often see choppy audio and video freezes. QoS ensures RTP packets get priority — protecting customer calls, sales demos and remote meetings.
DSCP tagging & switch trust
Configure phones and clients to mark RTP as EF (DSCP 46). Switches must trust DSCP at access ports and maintain tags upstream. Firewalls and WAN routers need QoS policies to keep markings intact over FTTP, SOGEA or Leased Lines.
WAN queueing & guest shaping
On WAN links, allocate a dedicated high-priority queue for EF traffic. Shape guest Wi-Fi and bulk downloads so calls never starve. With Leased Lines, end-to-end QoS is available; on FTTP/SOGEA, LAN/WAN QoS still protects call quality locally.
Monitoring & alerts
Use monitoring tools to track MOS scores, jitter and packet loss. Alerts notify IT teams before end users notice. Monthly reports prove QoS effectiveness and help justify leased line upgrades.
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Recently asked questions
Does QoS work over the public internet?
QoS applies mainly to your LAN and WAN. With Leased Lines, providers extend QoS end-to-end. On FTTP or SOGEA, local QoS still protects your uplink and avoids internal congestion.
Do softphones like Teams & Zoom support DSCP?
Yes. Microsoft Teams and 3CX can mark packets. We verify with packet captures to ensure DSCP tags are preserved through your network.
Will QoS stop guests slowing down calls?
Yes. By isolating guest Wi-Fi on its own VLAN and applying bandwidth caps, guest devices can’t impact your business VoIP or video traffic.