What issues can SIP ALG on the router cause?

There are various ways SIP ALG can impact VoIP service. These often happen without the user knowing and can include:

• One-way or no-way audio, intermittently or consistently
• Inbound or Outbound calls fail to connect
• Audio cuts out completely while on a call and doesn’t return
• Phones ring and can’t be answered
• Phones do not ring when called
• Calls go straight to voicemail for no known reason
• Faxes do not complete

Disabling SIP ALG on the router may help resolve the issues above. These are the general steps to change this setting in most router models:

1. Login to the router’s user portal
2. Navigate to the Advanced Firewall settings
3. Ensure that SIP ALG (Application Layer Gateway) is disabled

Refer to the router user manual for specific steps on how to disable SIP ALG or contact your Internet Service Provider for assistance.

Note – SIP ALG does not cause problems such as static, echo or poor audio quality, these are generally due to network (Internet) connectivity issues.

If you still experience issues after completing the above troubleshooting steps, please contact our Customer Care team for further assistance.