iPhone OS 3 remove O2 web compression

O2 has previously allowed circumvention of web compression with the username 'bypass' instead of 'vertigo' however I noticed the new APN idata.o2.co.uk which arrived with OS 3 doesn't respect it. To browse free of the horrid compression you'll need to change the APN back to the former mobile.o2.co.uk and either cycle the phone or toggle Airplane Mode to activate the connection.

System Preferences > Network > Cellular Data Network > Cellular Data > APN

I didn't know it used web compression. What are the pros and cons of turning it off?

My understanding of the term "web compression" relates to the gzip compression that is used by a lot of sites these days to reduce the network delays in getting date to your browser. I run gzip compression on a web site I operate for all browsers that can accept it, since gzip is a lossless compression algorithm, and the time taken to compress web traffic in the server is normally far less than the delay benefit of doing so.

Are you saying that O2 compresses uncompressed web traffic in order to speed up transfer across the wireless leg of the Internet link? Or is "circumvention" of "horrid compression" a reference to some other technique?

Turning it off improves the quality of graphics but due to increased file size takes longer to download as well as consuming more data. On slow or metered connections web acceleration can be useful but I prefer to see the web on my iPhone as it looks on my desktop computer, without fuzzy images.

Not the gzip method, to be honest I don't know the correct technical term for it but I imagine O2 use a form of HTTP compression whereby certain MIME types such as images are compressed and delivered to the end user from the cache. I know some browsers have plugins to fool web servers into believing the content is being delivered to non mobile platforms but on the iPhone you need to connect as 'bypass' to circumvent O2's web acceleration technique.

They recompress jpegs and hugely degrade their quality. It's fine for casual browsing but if you're showing your photos to people it looks bad.

Agree, that's why I'm obsessed with having it bypassed.

Ah! I hadn't noticed, as I tend to show off my photos using the built-in photos facility rather than the web services.

Not just jpegs though, images generally such as the banners, buttons and generally any graphics detail you might see on a website.

Well, I'm clearly not discerning enough to be let loose with an iPhone. When do the fuzz come and take mine away?

Edited by deleted (Sun 21-Jun-09 21:56:10)

Ha, clearly you've confounded the fuzz so you're safe gzipper

Thanks for that bosie - the net is back to being fast.

Top tip!

It looks like changing the APN back to mobile.o2.co.uk and username vertigo and password bypass no longer works.



I still get compressed images and such after changing access points and rebooting.

Tried on my E71 and the same results, compressed images....

I haven't tried it, but I think Bosie said User name should be bypass instead of vertigo. Not sure what password is required.

that's right
username is bypass
password is password