A mobile terminated call vs. a mobile originated call is the difference between 
a customer being able to reach out to the device remotely and communicate.  

Explanation of each below.

1. Mobile Originated Modem
      If a modem is using an account that is "Mobile Originated", this means the modem 
will not accept inbound transactions of any kind.  As such, this modem's only method 
of communication is an outbound message.  The modem will have to originate the communication 
to an outside resource (such as going to www.google.com from a browser).  At that point, 
the website's response is allowed in because it was originated by the modem.  An example of 
Mobile Originated accounts would be AT&T's WAP.CINGULAR and ISP.CINGULAR APN's.  


2. Mobile Terminated Modem
      If a modem is using an account that is "Mobile Terminated", this means the 
modem will accept inbound transactions/queries.  These accounts do not require 
the modem to start the communication.  This is the required account for anyone 
trying to do data collection/telemetry as well as anyone that would like to 
make changes to their modem remotely.  Examples are standard Verizon accounts, 
standard Sprint Vision accounts and AT&T's WWAN.CSS APN (if the customer's portion of the APN 
is set to allow mobile termination).