Thanks for your answer.

The client connects to the server with telnet. i.e. on the terminal emulator
window of the client the user sees "login:" and then logs on to the unix server.

Below is what "ps" command displays - note that there is no ip, but just the termid - pts/29:
ka2d2 28144 28142 0 Nov 20 pts/29 0:00 -sh

I want to find out the ip of the client from which the user "ka2d2" logged in the server.