TCP/IP ethernet

Hello .
I need a program in any language that can gets 'data' and the 'destination address' from the user and sends the data to the destination while using TCP/IP in an ethernet .
also a program that recieves packets from ethernet and gets the data from the packet .
usually these two programs are in one .

can anyone help me ?
thank you .

ps It is a part of a project and the project manager told us this program has been written before , just find it .I am not a lazy girl and it is not a homework .

So what's the question?

Find the program

Or write something which works the same

Your description covers anything from FTP to Instant Messaging

I am trying to find it but the problem is :
what I have found (or find) is usually a demo version or a part of a code not the main .

what kind of data do you have in mind..

and what the OS on both source and dest. machines?

I didnt understand what you mean of " what kind of data do you have in mind.."
and
I need the program and if it be for WINDOWS I use windows as the OS , if the program be for linux I wil use linux (the program is more important)
tnx

I just thought about giving you a non extrnal program solution.

what i mean by "data type", i'm talking about simple text messages, or files...

with simple text messages on a windows platform i would suggest "net send", it's very simple!

and as for files, you have ftp and tftp, take your pick.

you can write a batch file to do the majority of this.

as for analysis packets... do you mean a packet sniffer like etherreal?
http://www.ethereal.com/