INT 21 - Novell NetWare - MESSAGE SERVICES - OPEN MESSAGE PIPE
        AH = E1h subfn 06h
        DS:SI -> request buffer (see below)
        ES:DI -> reply buffer (see below)
Return: AL = status
            00h successful
            FEh out of dynamic workspace
Note:   this function is supported by NetWare 4.0+ and Advanced NetWare 1.0+
SeeAlso: AH=E1h/SF=07h,AH=E1h/SF=08h

Format of request buffer:
Offset  Size    Description
 00h    WORD    length of following data (max 66h)
 02h    BYTE    06h (subfunction "Open Message Pipe")
 03h    BYTE    number of pipes to open (01h-64h)
 04h  N BYTEs   list of connection numbers

Format of reply buffer:
Offset  Size    Description
 00h    WORD    (call) size of following results buffer (max 65h)
 02h    BYTE    number of connections
 03h  N BYTEs   list of results
                00h successful
                FEh incomplete (target half not yet created)
                FFh failed