If you can make calls but audio is missing, or you’re getting a “number not available” message, here’s what to check.
What You Might Be Experiencing
- You can hear the other person, but they can’t hear you
- They can hear you, but you can’t hear them
- Calls connect, but there’s silence
- You get a “number not available” message
Quick Checks First
1. Restart Everything
Switch off:
- Router
- VoIP device
Switch back on:
- Router
- VoIP device
Give it a minute before testing again.
2. Check Your Internet
VoIP depends on a stable connection.
- If your internet is slow or dropping, calls will fail or lose audio
Fixing One-Way Audio
This is almost always a network issue.
Most Common Cause: Router / NAT / Firewall
Your router may be blocking part of the voice traffic.
Quick test:
- Use a softphone (Zoiper / GS Wave) on mobile data
- If it works there → your router is the problem
What You Can Do
- Restart your router
- Disable SIP ALG in router settings (if available)
- Avoid double NAT setups (router behind another router)
If you’re not comfortable changing settings, log a support request.
Device or Codec Issue
- Incorrect codec settings can break audio
- Reset or reconfigure your VoIP device if needed
Fixing “Number Not Available”
1. Check the Number Format
- Always dial the full number
- Include area code (e.g. 021, 011)
2. Test Other Numbers
- If all numbers fail → likely configuration issue
- If only some fail → likely routing issue
3. Routing Issue (Provider Side)
Sometimes the route to a specific network fails.
👉 Provide support with:
- The number you called
- Date and time
Still Not Working?
Have this ready before contacting support:
- Your VoIP number
- The number you’re calling
- Time of the issue
- What exactly happens (silence, error, one-way audio)
Straight Talk
If nothing changed on your side and this suddenly started happening, it’s usually:
- Router behaviour
- Network routing
- Or registration hiccups
Not magic. Just VoIP being VoIP.