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Why SIP ALG should be turned off in your router.

SIP ALG (Application Layer Gateway) is a feature on routers that is designed to open and ‘inspect’ the data packets that pass through it. It is enabled by default on most routers, but with modern providers, it is not necessary and can often cause issues with registration and call setup.  To see if your router has SIP ALG enabled, follow the steps here.

What Issues Does SIP ALG Cause?

SIP ALG was created as an attempt to help people using older VoIP equipment, but it often causes more problems than it solves. It can lead to:

How To Turn Off SIP ALG

To avoid any potential issues related to SIP ALG, it is best to turn it off. This is relatively easy to do, although it will depend on the make and model of your router. The following steps will help guide you:

  1. Log into your router's configuration page.
  2. Look for an option related to SIP or VoIP.
  3. If you find it, uncheck the box or select "Disable".
  4. If you can't find it, try searching for "ALG" or "SIP ALG".
  5. If you still can't find it, contact your router's manufacturer for assistance.

Once you have turned off SIP ALG, restart your router and any connected devices. This should help resolve any issues that you might have been experiencing.


SIP ALG is not necessary with most modern providers, and it can often cause more issues than it solves. To prevent any problems, it is recommended to turn off SIP ALG on your router. If you need any additional help, please get in touch with your provider.