What exact null modem do I need

[nay27uk]

I am trying to flash a box supper and a replay lite.
But canot get either to conect what is the exact type of null modem I need to use here are the alternatives

Null modem without handshaking
Null modem with loop back handshaking
Null modem with partial handshaking
Null modem with full handshaking

The one I have is the Null modem with full handshaking.

Please help

[ASEK]

lappie or pc ? lappie needs a special serial connector of types.