null modem for testing

hi all..

sorry for repeating the same question many times,

i just set up a null modem, i am using this as reference :
DB25 DB9
-- -
2 TD ---- 2 RD
3 RD ---- 3 TD
4 RTS ---- 8 CTS
5 CTS ---- 7 RTS
7 GND ---- 5 GND
6 DSR -+
+--- 4 DTR
8 DCD -+
+- 6 DSR
20 DTR ---+
+- 1 DCD

it is working and i can see the output from server until i find OK, but i can't send any command after completed the test.
is there any design for null modem for a certain sun server???
still struggling and moving very slow.....

i will appreciate for any help...

thanks