3.1.1 Abstract Data Model

This section describes a conceptual model of possible data organization that an implementation maintains to participate in this protocol. The described organization is provided to facilitate the explanation of how the protocol behaves. This specification does not mandate that implementations adhere to this model as long as their external behavior is consistent with that described in this specification.

The following data model and states are common for the client role and the server role of the protocol:

Modem state: A data element that describes the current state of the modem device. The modem device can be in one of two states: offline command mode or online data mode.

Offline command mode state: In this state, there is no call-up and the modem is accepting AT Commands via IrDial messages. This is the state in which all sessions are started.

Online data mode state: There is a call-up and the modem can receive and transmit data.

IrDial-TTP connection state: A data element that describes the current state of the TinyTP connection that is used for PPP Over IrDA Dialup Protocol communication. The server and the client can be either in an IrDial-TTP connection established state or in an IrDial-TTP connection not-established state.