# IMGT application overview

An IMGT application typically performs the following tasks:

IMGT application flowchart

The following table summarizes the illustrated tasks:

In this phase... | The application...
--- | ---
Initialize Natural Access | Initializes Natural Access services and creates one context for each B channel and D channel.
Initialize NMS ISDN protocol stack | Calls isdnStartProtocol to start up an ISDN protocol stack instance on each D channel context.
Start IMGT session | Invokes imgtStart to start an IMGT session on each D channel context.
Perform tasks | Uses the standard Natural Access event structure to send IMGT messages and receive IMGT events.
Stop IMGT session | Invokes imgtStop to end the IMGT session.
Stop protocol stack | Calls isdnStopProtocol to stop the ISDN protocol stack instance on each D channel context.