Format of Alloy request block:
Offset	Size	Description	)
 00h	DWORD	pointer to packet to send
 04h	WORD	packet size in bytes (1-4096)
 06h	BYTE	number of destinations for packet (max 1Fh)
 07h 31 BYTEs	destination user IDs (FFh = broadcast to all except sender)
 26h 31 BYTEs	destination channels (FFh = first available channel)
 45h 31 BYTEs	return destination statuses