4.9.2. Nonstandard Facility Message (Q.931)

Use the gc_Extension( ) function in asynchronous mode with an ext_ id (extension ID) of IPEXTID_SENDMSG to send nonstandard facility (Q.931 Facility) messages. The target_type should be GCTGT_GCLIB_CRN and the target_id should be the actual CRN. At the sending end, a GCEV_EXTENSIONCMPLT event is received indicating that the message has been sent. At the receiving end, a GCEV_EXTENSION event with the same ext_id value is generated. The extevtdatap field in the METAEVENT structure for the GCEV_EXTENSION event is a pointer to an EXTENSIONEVTBLK structure which in turn contains a GC_PARM_BLK that includes all of the data in the message.

The relevant parameter set IDs and parameter IDs are:

• IPSET_MSG_Q931
  • IPPARM_MSGTYPE - Set to IP_MSGTYPE_Q931_FACILITY.
• IPSET_NONSTANDARDDATA
  • Either
  • IPPARM_NONSTANDARDDATA_DATA - Actual nonstandard data. The maximum length is MAX_NS_PARM_DATA_LENGTH (128).
  • IPPARM_NONSTANDARDDATA_OBJID - Object ID string. The maximum length is MAX_NS_PARM_OBJID_LENGTH (40).
  • or
  • IPPARM_NONSTANDARDDATA_DATA - Actual nonstandard data. The maximum length is MAX_NS_PARM_DATA_LENGTH (128).
  • IPPARM_H221NONSTANDARD - H.221 nonstandard data identifier.

Note: The message type (IPPARM_MSGTYPE) is mandatory. At least one other information element must be included.

See Section 6.12, IPSET_MSG_Q931 Parameter Set and Section 6.14, IPSET_NONSTANDARDDATA Parameter Set for more information.

The following code shows how to set up and send a Q.931 nonstandard facility message.

	char ObjId[]= "1 22 333 4444";
	char NSData[]= "DataField_Facility";

	GC_PARM_BLKP    gcParmBlk = NULL;

	gc_util_insert_parm_val(&gcParmBlk,
				                         IPSET_MSG_Q931,
				                         IPPARM_MSGTYPE,
				                         sizeof(int),
				                         IP_MSGTYPE_Q931_FACILITY);
	
	gc_util_insert_parm_ref(&gcParmBlk,
				                         IPSET_NONSTANDARDDATA,
				                         IPPARM_NONSTANDARDDATA_OBJID,
				                         sizeof(ObjId),
				                         ObjId); 
							gc_util_insert_parm_ref(&gcParmBlk,
	                         IPSET_NONSTANDARDDATA,
				                         IPPARM_NONSTANDARDDATA_DATA,
				                         sizeof(NSData),
				                         NSData); 
	gc_Extension( GCTGT_GCLIB_CRN,
	              crn,
	              IPEXTID_SENDMSG,
	              gcParmBlk,
	              NULL,
	              EV_ASYNC); 
	gc_util_delete_parm_blk(gcParmBlk); 

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