Do You Have Wi-Fi?
By Charles Miller
The Computer Corner
There is something a lot of users of Wi-Fi-connected devices have seen at one time or another, although they might not know what to call it. What I refer to is a “captive portal,” sometimes called a UAM (Universal Access Method) or “port 80 intercept.” These are all names for a special web page you could land on when you try to use your laptop, tablet, or smart phone in public.
I see this scenario played out with regularity at my favorite coffee shop. Someone comes in carrying one of the aforementioned portable devices and sees an unsecured Wi-Fi access point (no password required). “Whee!” they say to themselves as they connect and try to use their email app, but it does not work. They then try their Facebook app, but it too goes nowhere. Then they may try their web browser to see if they can pull up some site such as yahoo.com, and when they do, a different page is displayed.
“What the &%#!” they sometimes mutter, “I know I typed in yahoo.com, so why did I get to this page that says “Welcome to the Coffee Shop?” That page says, “Enter the username and password off your receipt to prove you paid for a cup of coffee, then you can use the Internet for a bit.” That is what a captive portal does.
Sometimes a captive portal does not require any login credentials. A bus I recently rode merely required I check the box where it said I agreed to abide by all the rules and regulations of the bus line. Another captive portal on an airplane required payment by credit card before granting access. Airlines, airports, and hotels use this method to boost revenue. A smart traveler knows to ask not only “Do you have Wi-Fi?” but also “How much does it cost per hour or per megabyte?”
Over the years, I have had some experiences when it was necessary to bypass a captive portal. You will not be able to do this at the coffee shop or airport, but an example I can site is an apartment building in New York City that provided Internet access for all tenants. The management used a captive portal to ensure that only tenants who lived in the building were sharing the Internet service.
One tenant asked management if they could do away with the need to enter apartment numbers and passwords every time to access the Internet, and management refused. Then the tenant asked me. I knew that the correct router in the tenant’s apartment, specifically programmed, could make life easier for the users. This is a case where the tenants were absolutely not trying to gain access to something they had not already paid for. They were just sick and tired of being forced to enter their apartment number and password 30 or more times a day. Working remotely, I programmed the router they bought so that it would authenticate to the captive portal. The tenants no longer had to type in their password because the router was authenticating who they were. The building management seemed to be okay with that solution because they were still getting paid.
One fact that users of a captive portal need to remember is that all access can be censored and certain programs blocked. If Skype will not work at the hotel or while on an airplane, do not panic. Skype might work just fine when you get home; the hotel or airline did not want you using up their bandwidth, so they blocked Skype.
Charles Miller is a freelance computer consultant, a frequent visitor to San Miguel since 1981 and now practically a full-time resident. He may be contacted at 415 101 8528 or email FAQ8 (at) SMAguru.com.