The unitdata request message is used by the application to send a packet to the far end (SCCPUDataRqst) when employing the SCCP connectionless services (class 0 or 1) or is received by the application to indicate an incoming data packet from a far end point (SCCPUDATIND).
typedef struct sccpUdataRqst
{
SccpProtoClass protoClass; /* protocol class (M) */
SccpAddr calledPty; /* called party address (M) */
SccpAddr callingPty; /* calling party address(M) */
SccpEOS eos; /* end-of-sequence flag (M - class 1 only) */
U8 spare1; /* spare for alignment */
U8 spare2; /* spare for alignment */
U8 spare3; /* spare for alignment */
SccpImportance importance; /* reserved for ITU-96 importance (O) */
SccpIsni isni; /* reserved for Ansi-96 ISNI (O) */
SccpData data; /* data (M) */
} SccpUdataRqst;