Int 21 Fn B301  U - Novell Netware - Check Signature Level???              [N]

   AX = B301h

Return: AX = 0000h if supported???
       BX:CX indicate signature level (see #1489)

Note:  this function appeared with the packet signing/Large Internet Packets/
     IPX Checksum-aware NetWare shells

See Also: AX=B300h,AX=B304h,#2561 at INT 2F/AX=7A20h/BX=0000h

(Table 1489)
Values for signature level indicator:
 0000h:0000h = signature level 0
 0002h:0000h = signature level 1
 0202h:0000h = signature level 2
 0202h:0202h = signature level 3