You mean an FTP install right? As you can't boot a blank system from FTP, the closest you can do is use TFTP/BOOTP to server images to a machine that has a boot ROM on the network card that downloads the imagine and then runs that to get the rest of the OS down over the network and then fires up. You can also accomplish this using a linux boot disk to drive the network card but I've never played with either - there is a diskless howto somewhere at
http://www.linuxdoc.org
If you are going to do an FTP install the you'll need to boot your client machine using some boot floppies, and have the install CD mounted in another *nix box somewhere, then point your installer to that dir with some username and password - I can't say its something I've ever done, I tend to use NFS installs when I'm working over a network - in which case you just export the install CD from the existing *nix box and point you install to that dir.
A little more info would be useful.
cheers
Jamie...