16 November 2008

Building HotSpot

Ever wonder how to build your very own wifi hotspot? If you followed my previous posts, I hope you manage to build your own home network and that is suffice for the first step in building wifi hotspot.

Next things to consider are how to manage your network, you certainly don't want anyone just joining your wireless network right? that is if you don't want to build free for all hotspot.

You also don't want people eating all your bandwidth, somehow you need to limit the hotspot users, and limit their access so they won't be able to join your internal LAN.

If you want these features in your hotspot, you probably going to need something that is called captive portal.

What captive portal does is like this, if someone join your wireless network, he or she then open a web browser, the captive portal would then redirect the browser to your html page, no matter what url requested.
That html page of yours is typically a welcome page or a login page so only certain people can make use of your wireless network.
This is great for public wifi hotspots.

There are many captive portals that you can find, free or commercial ones, the one that I'm familiar with is from publicIP, it's called ZoneCD.

Most of the captive portals that you can find might work the same way, they need you to put a PC between your wireless device and your internal network or internet router.
This is the image I got from the publicIP ZoneCD:

The PC should have 2 NIC (Network Interface Card), one goes to your internal LAN, the other goes to wireless LAN.
That PC would do all the authentication of the wireless users, the bandwidth limitation, etc.

What I like most about ZoneCD is that it's a Live CD, you just need a working PC, put in the CD and then the PC boots from the CD, nothing needs to be installed.
Sure it's based on Linux/UNIX, but you don't need to know anything about Linux, you only need to know how to operate a PC, so they say.

You can do homepage redirection, content filtering for porn sites or downloads, the ZoneCD has built in firewall, you can also modify the login page to conform your own taste or give it a logo of your company.