3.2.5.1 Receiving a Dial Message

  • Article

When a Dial Message arrives, the server can be in one of two modes: offline command mode or online data mode.

If the server is in offline command mode when a dial message is received, the server responds by sending the same Dial Message. This response is called "echoing the message." Upon echoing the message, the server executes the AT Dial command sequence and sends a Dial Response Message with the Response field string. If the dial response message Response field string value is "CONNECT <speed>", the server moves to the online command mode state; otherwise it remains in the offline command mode state.

If the server is in online data mode when a Dial Message is received, the server treats it as a regular Data Message. That is, it does not execute the AT Dial command sequence and therefore takes no action.