Differences between WiFi access with and without a webpage access?

Question

At cafes providing free WiFi two different methods of connecting appear. The first is where you choose the name of the WiFi, and then you are prompted for the username and password. The second is where you select the WiFi name and then are connected automatically and when trying to use the access the first time a webpage appears asking for either accepting the terms and conditions or entering the username and password there in the HTML fields.

Is the second method using a proxy / web proxy? How could someone with a typical home wireless internet connection have a webpage like this? What are the benefits for having such a access method? Does it allow you to maybe log and remember who connected and when?

Most colleges I have visited have the webpage entrance point as well. Could someone explain how these two methods work, differ, and benefits for each?

Answer 1

The second method you are describing is commonly called a Captive Portal.

Basically you intercept every packet and redirect it to a login page if the user is unauthenticated. Some routers have captive portal functions built in but you may also use a standard pc for this.

Pros:

• Easy to limit time or filter content for certain users (ie. Student and Teacher login)
• Not just for wifi, works on wired network too.
• Existing user database can be used (ie. student id, company e-mail)
• Versatile

Cons:

• Clients without web browser/keyboard can't connect (VoIP-phones, network webcams etc.)
• Extra hardware / more expensive router needed
• Can affect speed
• Complicated