Known Issues:

  1. SIP ALG is enabled by default, causing intermittent call and phone feature failures.
  2. DNS Proxy is enabled by default, causing intermittent registration failures on Polycom phones.
  3. The firewall by default is set to ClearSailing, which allows all outbound traffic but filters inbound traffic.  The phones work well with this setting, but if you set the firewall above ClearSailing, it will cause intermittent phone registration failures.


  1. Telnet to the Netopia from a computer that is behind the Netopia gateway. 
    • Use PuTTY or the OS’s native telnet client. 
    • The default IP is
    • Log in using “admin” as the username and the Device Access Code printed on the Netopia as the password.
  2. Enter the following commands one at a time and press enter after each line:
    • config
    • set ip sip-passthrough off
    • set dns primary-address
    • set dns secondary-address
    • set dns proxy-enable off
    • set security firewall option low
    • set diffserv option on
    • save
    • exit
    • exit
  3. Login to the router by typing in the IP of the router into the address bar of any web browser. 
    • The default IP is
  4. Under where it says Speed, tell Intermedia the downstream & upstream in kbps so we can document these values.
    • This is the Line Rate, which are the internet bandwidth speeds you are paying for. 
    • We need this information if you experience call quality problems or other phone issues.
  5. Warn everyone in the office that you will need to restart the router to apply the changes. 
    • Once they're ready, click on Restart Router.

Additional Resources:

  1. Recommended Routers.
  2. Recommended Switches.
  3. Recommended LAN Configurations.
  4. Network Ports and Protocols for HPBX phones.