Configure QoS on an SMB router for stable VoIP.
QoS is only useful when the bottleneck is in your control, so on the WAN uplink. DSCP marking EF (46) for RTP, CS3/AF31 for SIP, plus a traffic shape on the uplink.
Try this first
- 1Set DSCP marking on the PBX side and on phones (EF for audio, AF31 for signalling).
- 2Build a QoS policy on the router that gives the voice class priority.
- 3Shape the uplink to 90 percent of real-measured speed (measure, not the contracted spec).
- 4Test with several simultaneous calls plus heavy download at once.
When to bring us in
QoS has no measurable effect: the bottleneck is probably at the provider, not you, then QoS will not help.
See also
- Voys, BelXS or RoutIT, which cloud PBX fits?Three popular NL platforms, differences are admin UI, partner model and per-user price.
- Teams Phone: Calling Plan, Direct Routing or Operator Connect?Three ways to connect PSTN to Teams, cost and management differ a lot.
- 3CX: self-host on VPS or take 3CX cloud?Self-host saves licence, but you own SBC, backup and updates.
None of the above fits?
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