This post focuses on gprs/ edge based internet settings (specially in Pakistan – ufone, mobillink, warid, telenor, zong) on iPhone.
I have got comments on various posts on gprs settings post that the settings don’t 
work for many people (even those which i can confirm myself that they are working). The reason for them to not work are not that the settings are wrong, but some minor settings or stuff that’s usually overlooked by us.
If you entered someone’s verified gprs settings for your cellular data network, and it’s still not working, then go through this checklist and make sure that these are correct.
If you have any other item to be added in this check list too, or if after checking them internet still don’t work, then do let me know.
- Re check if settings entered are correct
- make sure that there is no extra space before or after any settings item
- restart your iPhone after entering the settings
- make sure that My Number is in correct format
- confirm that your sim has internet / gprs activated on it (you can do it by calling the service center or by using it on some other cell phone)
- make sure edge is turned on and 3G is turned off on iPhone (jailbroken iPhones get their edge disabled sometimes – can be turned on via sbsettings)
- you have balance / credit in your sim! :p
Hope these simple things could fix the issue with your internet / gprs settings not working!