# Terminology

- SMS - Short Message Service i.e. text messages

- SMSC - Short Message Service Centre The system responsible for storing and forwarding messages

- MO - Mobile Originated A message on its way from a mobile or landline device to the SMSC

- MT - Mobile Terminated A message on its way from the SMSC to the mobile or landline device

- RX - Receive A message coming in to the Asterisk box

- TX - Transmit A message going out of the Asterisk box