A little over a year news broke: Vodafone UK had implemented a transcoder proxy data on your network so that all their customers connections passing through this system. Under the guise of making available to all terminals any existing website, completely changed the aspect of it, adding advertising, direct access to Vodafone Live! and what's worse, changing the style sheets of the portals, with your work lost its original appearance.

The international movement within the sector was considerable. People like Andrea Trasatti or Luca Passani , true gurus of adaptation, revolted against the measure. Many people I criticized.

The problem was not only the appearance of portals, that is what is seen directly, the major problem was (is) that they were carrying one of the basic concepts of adaptation for mobile phones: the UserAgent . Although there is in all web browsers, the UserAgent is particularly important in a mobile device and that identifies you, gives you information on the same make and model so that, with a good database of terminals (eg wurlf ), you obtain compatibility (video, mp3, mms ...) and screen sizes. By filtering out UserAgent removed the ability to deliver content compatible with that terminal. Think of the mobile Java games where it is essential to know which model you have the customer since we have to give a file compiled for the same.

After some protests, from Vodafone UK decided to send the original phone UserAgent but in a separate HTTP header, which would have to modify all your developments because of this wonderful idea.

Finally pulled the sleeve two solutions to the transcoder:

• If your domain is. Mobi not alter the content and assuming that it is content optimized for small devices.
• A whitelist where, if you send your domain, failed to filter and adapt.

Actually I do not know if the second method was to work sometime. The first yes.

In October of last year's debacle came to Spain. Vodafone is putting the famous transcoder and all our mobile portals lost their look & feel as well as being modified to include all direct links to Live!. We were also cries of alarm .

Here the problem was worse, they never send the original UserAgent. I do not know if now they do, but at the time did not. This measure of Vodafone did much damage to the sector.

Now, almost a year later, I discovered, quite by chance, that Movistar also has the famous transcoder proxy, but for now it seems that do not abuse it. They do not change anything visually or hide the UserAgent, but adjusting a few things. I explained the situation that I was crazy for two days.

Preparing a site for a major promotion that I found on a Nokia N95 unseen images to size. Our platform automatically adapts the image size depending on the terminal screen width of the client (obtained from the UserAgent). As it turns out we were on the server generating the images correctly, 240px wide, while on the phone were receiving a 95px wide. Impossible!

We tried the same phone but with SIM cards from other carriers and voila, it worked perfectly. Finally I try with other terminals and discover that, indeed, are adapting images, imagine that to reduce network traffic and optimizing bandwidth. The problem of the N95 is that, for some strange reason, I have incorrectly configured in your database terminal, and instead of putting the real size of screen that has (240 × 320), we have 95px width, even maybe it's the default size that returns the transcoder if there is no such terminal in the database, because even worse, the N95 is one of the most popular devices despite its cost.

What do I do now when the client tells us that the site looks bad on your N95? Do you believe that the fault lies with Movistar?