This article outlines the steps to disable SIP ALG and set proper DNS servers for reliable VoIP performance.
SIP ALG (Session Initiation Protocol Application Layer Gateway) is enabled by default on the AT&T Arris BGW210-700 router. This can cause VoIP-related issues, such as dropped calls, registration failures, or poor call quality. Additionally, Polycom phones may experience registration issues due to inefficient DNS settings.
Known Issues
- SIP ALG is enabled by default – This can interfere with VoIP phone communication and should be disabled.
- DNS DHCP servers need to be adjusted – Changing the default DHCP DNS servers to efficient alternatives, such as Google’s public DNS, helps prevent Polycom phone registration failures.
Resolution
Step 1: Connect to the AT&T Router
- Plug a computer directly into one of the three Yellow Ethernet ports on the AT&T Arris BGW210-700 router.
- Open a web browser and enter 192.168.1.254 in the address bar.
- Locate the Username and Password on the barcode sticker at the back of the router and use them to log in.
Step 2: Disable SIP ALG
- Navigate to Firewall > Advanced Firewall.
- If prompted, enter the Device ID (found on the barcode sticker of the router).
- Locate SIP ALG and set it to OFF.
- Set the following options to OFF as well:
- Authentication Header Forwarding
- ESP Header Forwarding
- Click SAVE to apply the changes.
Step 3: Update DHCP DNS Servers
- Contact AT&T Support and request to change the DHCP DNS servers on the modem to Google’s Public DNS.
- Provide the following DNS server details:
- Primary DNS server: 8.8.8.8
- Secondary DNS server: 8.8.4.4
- Confirm with AT&T that the changes have been successfully applied.
Additional Notes
- After making these changes, restart any VoIP devices and test for proper connectivity.
- If VoIP issues persist, verify that the settings are saved correctly and reboot the router.
- For Polycom phones experiencing registration issues, ensure they are using Google’s Public DNS.