==== Mediatrix ====
  * http://www.media5corp.com/en/voip-gateways/mediatrix-3000-series
  * http://mediatrixsdk.media5corp.com/index.php?title=Installing_Asterisk
  * http://www.media5corp.com/repository/3000/configuration%20notes/Configuration_Notes_0296_Mediatrix%203000%20with%20Asterisk.pdf