Usage information overview

This section provides the detailed encoding reference for:

Data structures

C-language definitions for all token structures, information element structures, event structures, and associated constants are provided in the isupmsgs.h file. For information about the information elements used for generating specific ISUP messages for each switch type, refer to Sending ISUP protocol messages and Receiving ISUP protocol messages.

Coding of presence indicators

Each token within an information element and each information element within an event contains a presence indicator to specify whether or not to include it in an outgoing event, or whether or not it was received in an incoming event.

Presence indicators are coded with the following values:

#define NOT_PRESENT   0   /* field not present in incoming msg or
                           * not to be populated in outgoing msg       */
#define PRESENT       1   /* field is present in incoming msg or
                           * should be *included in outgoing msg       */

The definitions for the presence indicators are included in the isupmsgs.h file.