rcm3700 ip problem

Hello everybody
I'm facing a problem in a rcm3700 module.
This module works as a server in port 23 .
We can connect to this in module when it has the ip 192.168.0.xxx but never when it has 
the ip 10.179.237.xxx. 
We have try with subnet 255.0.0.0 and 255.255.255.0. but nothing happens.
We can ping it but we cannot connect to port 23.
Because the net 10.xxx.xxx.xxx is a b type we must configure it in another way ?


Best regards to all
Theodore Politis.