How to Stop Ghost Calls on Grandstream HT801

Ghost calls (calls that ring but have no one on the line) can be annoying. Here's how to stop them on your Grandstream HT801:

What Causes Ghost Calls?

  • Port scanning attacks
  • Misconfigured firewall
  • SIP registration issues
  • Router SIP ALG problems

Solutions

1. Enable Anonymous Call Rejection

  1. Access your HT801 web interface (usually http://192.168.1.1)
  2. Go to FXS Port settings
  3. Enable Anonymous Call Rejection
  4. Save and apply

2. Configure Firewall

  1. Go to Security → Firewall
  2. Enable Firewall
  3. Set Trusted IP to your VoIP provider's IP range
  4. Block all other SIP traffic

3. Disable SIP ALG on Router

SIP ALG (Application Layer Gateway) can cause issues:

  1. Access your router settings
  2. Find SIP ALG or Application Layer Gateway
  3. Disable it
  4. Save and restart router

4. Update Firmware

  1. Check current firmware version
  2. Download latest firmware from Grandstream
  3. Update via web interface
  4. Factory reset if needed (backup settings first)

5. Change SIP Port

  1. In HT801 settings, change SIP port from default 5060
  2. Use a non-standard port (e.g., 5061)
  3. Update port forwarding on router
  4. Update VoIP provider settings

If ghost calls persist after trying these solutions, contact our support team for further assistance.