Sending messages across an established link

Once NMS ISDN is in the DATA_LINK_ESTABLISHED state, the application and the remote equipment can exchange messages. To send a packet of data, the application sends either of the following messages:

No confirmation is returned in response to either of these requests.

The following illustration shows the sequence of messages sent between the trunk, the stack, and the application when the application sends a message across an established data link:

seq_dlms.gif

When a packet is received from the remote party, the stack sends one of the following messages to the application:

The application does not confirm receipt of a packet.

The following illustration shows the sequence of messages sent between the trunk, the stack, and the application when the application receives a message across an established data link:

seq_dlmr.gif

If the data link is broken while NMS ISDN is in DATA_LINK_ESTABLISHED state, the stack sends DL_REL_IN to the application. NMS ISDN returns to the IDLE state.