Does UDP messages sent from the network get converted to serial for serial ports?

I have a PS TS MEI/4 which i have configured for UDP communications with all serial ports through the web UI.
I have written C code such that it reads and sends data from the network side of the server. I can receive data fine coming from any of the serial ports but when I try and send data back through there is nothing received.
I was wondering if the server outputs the data received from the network in the appropriate serial format through the serial ports?
when I use a loop back connector on one of the serial ports, I can successfully receive back the data that is sent from the server. I can not however receive it successfully within terminal such as PUTTY or COOLTERM.
If you have any other questions please ask, I am only new to this so I appologise if this is a silly question.