Note that this process will reboot your router - which will temporarily take your internet connection and phone service offline.
We recommend doing this in an off-peak period or outside of business hours.
Learn more about SIP ALG in our knowledge base article here: SIP ALG
Disabling SIP ALG
1. Log in to the router - the default address is http://192.168.0.1 with the defult login of admin / admin
2. Navigate to Advanced Setup > NAT > ALG

3. Untick the Enable SIP box

4. Click Save/Apply
5. Reboot the router
6. Test your internet connection to see when the connection comes back online.
7. In some cases, you may need to reboot your phones in order to re-connect them.