SIP ALG Detection

Table of Contents

What does SIP ALG Detection mean? How to fix it

What does SIP ALG Detection mean?

SIP Application-Level Gateway (ALG) is a feature on many modern routers designed to help VoIP traffic. Unfortunately, it almost always corrupts the encrypted packets used by modern VoIP systems like Agilico Connect. This results in calls dropping immediately upon answering, phones not ringing, or failure to transfer calls.

How to fix it

  1. Log into your Router: Access your router's web interface (usually 192.168.1.1 or 192.168.0.1).
  2. Find the Setting: Look under "Advanced", "WAN Setup", "Firewall", or "Security".
  3. Disable SIP ALG: Uncheck or disable the feature labeled "SIP ALG", "SIP Passthrough", or "SIP Helper".
  4. Reboot: Save the settings and physically reboot your router, then reboot your PC to clear any stuck sessions.