AirVoice APN settings for Firefox OS
AirVoice Internet & MMS APN settings
Open the Settings app in Firefox OS.
Go to Cellular & Data, Turn on Data Connection.
Scroll down and tap Data Settings button and get the screen to enter the APN Settings.
Go to Cellular & Data Message Settings
MMS Proxy: 22.214.171.124
MMS Port: 80
On Firefox OS, APN settings should be entered in correct case. For example, if you are configuring your APN setting with AirVoice Internet & MMS APN settings configuration above, make sure you enter APN as att.mvno and not as ATT.MVNO or Att.mvno.