Format of parameter block:
Offset	Size	Description	)
 00h	WORD	buffer for estimated communication cost in 220 msec ticks
 02h	WORD	buffer for return code (set to 0 before calling)
 04h	WORD	socket handle
 06h	DWORD	far pointer to IPC/SPP message buffer
 0Ah	WORD	length of IPC/SPP message buffer
 0Ch	WORD	option flags
		bit 0: asynchronous communication
		bit 1: reliable message
		bit 3: end of message
		bit 4: vectored I/O
 0Eh 16	BYTEs	socket address (IPC port of source)
 1Eh	WORD	not used (set to 0 before calling)
 20h	WORD	SPP connection id (0 for IPC messages)
 22h	WORD	request type (1 = data, 2 = connect SPP, 3 = disconnect SPP)
SeeAlso: #03447