Known Issues

  1. SIP ALG is enabled by default and cannot be disabled, causing intermittent phone call and feature failures. 
  2. DNS server addresses need to be changed to set of efficient DNS servers, like Google's DNS or another DNS, to prevent intermittent registration failures on Polycom phones.

Permanent Resolution

  1. Buy a Recommended Router if you do not have one already.
  2. Intermedia cannot setup the new router for you, but your IT or the manufacturer of your new router can help you. 
  3. You will need to move settings from the old to the new router to ensure your computers and other devices on the network work properly.
  4. Call Comcast to bridge your Cisco DPC3939B modem to the compatible router.

Temporary Resolution

  1. Login to the router.
  2. Click on Gateway > Connection > Local IP Network.
  3. Check "Assign DNS Manually" and enter:
    • Primary DNS: "".
    • Secondary DNS: "".
    • Save the changes.
  4. Reboot your modem, then your PCs and phones.