Firmware versions 4.00a and higher include support for roaming and the G.729 voice codec.
Unless your phone already has firmware version 4.00a or later, installation of this firmware will require you to input a unique license key. Installation of this firmware without the required license key will render your phone unusable.
All production after July, 2009 has firmware 4.00a or later, but there still may be some units in the field that have firmware earlier than 4.00a. License keys for some of these may be available at QuickPhones. (If we do not have it, it is no longer available.)
To obtain your license key, email the MAC address of your phone (located on the label inside the battery compartment) to email@example.com, and we will send you the license key for your phone.