Configuring an AT&T/Pace 5268AC for Hosted VoIP

Preliminary Information

Customers with business service through AT&T will not have a standard equipment setup. Rather AT&T provides the customer with a modem/router combination unit. No option exists for a standalone modem so in practically all Ringfree related cases, the AT&T unit must be configured to allow unhindered access to other devices behind it.

Previously AT&T was providing Motorola devices which could be configured in bridge mode in order to achieve the desired outcome. More recently they’re provicing customers with the Pace 5268AC modem/router combination unit which can not be configured for bridge mode.

Additionally, AT&T doesn’t provision static IP addresses in the same manner that is typical with most internet service providers. Rather they provision a range of sticky IP addresses (usually five of them) that will not change so long as the account and device provisioning does not change. Customer premises equipment can be configured to make use of any of the five IP addresses.


  1. Connect the CPE to one of the LAN ports on the Pace and then reboot the Pace.
  2. Navigate to the Pace’s administration interface (usually at and log in (the credentials, if not default, should be supplied by AT&T).
  3. Once logged in, navigate to Settings, then to Firewall, then to Applications, Pinholes, and DMZ.
  4. Select the CPE from the device list.
  5. Check the bubble for DMZ+ mode and click Save.
  6. Navigate to Settings, then to Firewall, then to Advanced Configuration and enter the password (which again should be supplied by AT&T if not default).
  7. Locate the Enhanced Security section.
  8. Uncheck both the Stealth Mode and the Block Ping boxes and click Save.