When Your Phones Sound Bad
A 12-part VoIP troubleshooting guide covering the most common call quality problems. Symptom-based diagnosis for choppy audio, one-way audio, dropped calls, echo, caller ID issues, and more.
Choppy or Robotic Audio on VoIP Calls
Choppy or robotic VoIP audio is caused by jitter and packet loss. Work through these seven checks systematically to find and fix the source.
One Way Audio: I Can Hear Them But They Can't Hear Me
One way audio on VoIP calls is almost always a NAT or firewall issue. Here is how to find and fix the blockage so audio flows in both directions.
Calls Dropping After a Set Amount of Time
VoIP calls dropping at exactly 30 seconds or 15 minutes? Those patterns point to SIP timer and NAT timeout issues. Diagnose each one.
Echo on VoIP Calls
Echo on VoIP calls comes from acoustic feedback, network hybrids, or latency-amplified reflections. Here is how to identify the type and fix it.
Calls Going Straight to Voicemail
When VoIP calls skip the phone and go straight to voicemail, the cause is usually registration, DND, forwarding, or routing. Here is how to find it.
Caller ID Not Showing or Showing the Wrong Number
Caller ID on VoIP travels through multiple systems that can each modify it. Here is how to trace outbound, inbound, and CNAM issues to the source.
Audio Delay and Talking Over Each Other
VoIP audio delay causing people to talk over each other? Find the latency source and fix it with these steps.
Phones Not Ringing for Incoming Calls
VoIP phones not ringing for incoming calls? Check registration, ring groups, routing rules, and network issues with this guide.
Call Quality Is Fine in the Morning But Bad in the Afternoon
VoIP calls sound worse in the afternoon? That pattern points to bandwidth saturation, ISP congestion, or peak-hour network overload.
Calls Sound Fine Internally But Bad on External Calls
Internal calls sound fine but external calls are bad? The problem is between your PBX and the outside world. Here is how to find it.
Static, Buzzing, or Humming on Calls
Static, buzzing, or humming on VoIP calls? It is usually electrical interference, bad cables, or PoE problems, not packet loss.
Fax Over IP: Why Faxing Over VoIP Is Unreliable and What to Do About It
Fax machines were built for circuit-switched lines, not VoIP. Learn why faxing over IP fails and which alternatives actually work.