
5 VoIP quality issues and the router settings that often help
Hi all! When your VoIP calls sound choppy or drop out from time-to-time, the instinct is normally to blame the provider. More often though, the fix is sitting in front of your eyes in your router's admin panel. Let me share a few settings worth checking before you open a support ticket.
One-way audio: disable SIP ALG
SIP ALG was built for help VoIP traverse NAT. Most implementations are buggy and actually break call setup. Our SIP ALG troubleshooting guide covers this for every major router brand.
Find it in your router's advanced settings and turn it off.
- Netgear: Advanced > WAN Setup > Disable SIP ALG
- ASUS: WAN > NAT Passthrough > SIP Passthrough, set to Disabled
Choppy audio: enable QoS
Quality of Service prioritizes voice packets over file downloads. Without it, a large file transfer can interrupt your calls.
Prioritize UDP traffic on port 5060 (SIP signaling) and ports 16384-32767 (RTP audio).
Router firmware bugs cause more VoIP problems than people realize. Check for updates, especially if your router is more than a year old.
Short DHCP lease times cause desk phones to frequently re-register with the VoIP service. Set lease time to at least 24 hours for devices that don't move.
We published more troubleshooting steps in our VoIP optimization guide.
When this goes wrong
On the phone system side, document your hunt group order, failover path, and what happens when the primary carrier blips—most "mystery" missed calls are routing or timeout rules, not bandwidth.
This breaks when triggers are too loose (overflow never sleeps) or too tight (callers still hit voicemail during real spikes). Revisit thresholds after marketing pushes and seasonality.
So tell me, what quality issues have you hit? Drop some symptoms in the comments and I'll try my best to help diagnose!