Fixing Common VoIP Problems: One-Way Audio, Registration & Jitter

Most VoIP problems come down to a handful of root causes: NAT/firewall issues, codec mismatches, or network quality. Here's how to diagnose and fix the most common ones.

One-way audio (you can hear them but they can't hear you)

One-way or no audio is almost always a NAT traversal problem. The signaling connects, but the media (RTP) packets can't find their way back.

• Enable NAT traversal / STUN in your softphone settings.
• Make sure UDP ports for RTP (typically 10000–20000) aren't blocked by your firewall.
• Avoid double NAT (router behind another router) where possible.
• Try switching transport to TLS, or enable rport/symmetric RTP.

Registration fails

1. 1Verify the host is dial.hellopbx.net and the port is 5060.
2. 2Re-enter the SIP password from your portal (reset it under SIP Accounts if unsure).
3. 3Check that your account isn't blocked and has a valid balance.
4. 4Confirm your firewall allows outbound UDP 5060.

Choppy or robotic audio (jitter & packet loss)

• Use a wired connection instead of Wi-Fi when possible.
• Enable QoS on your router to prioritize voice traffic.
• Switch to a lower-bandwidth codec like G.729 on poor connections.
• Run a speed test — you need stable upload bandwidth, not just download.