APN Settings for O2 service in UK + Blackberry

I am developing an application which requires connection to the internet. Till now i have been using Wifi and WAP 2 connection UID for Http connection and everything has been working fine. But now the client is telling that he wishes to use direct TCP connection as using WAP2.0 connection costs him a big amount. I am not having clear understanding about APN settin开发者_开发技巧gs. I have goggled a bit and appended 'deviceside=true' to the url and then set the APN in the Settings->Advanced Options->TCP/IP. But everytime I run the application, I am getting 'Timed Out' Exception. My client is using O2 carrier. I googled and found out that APN for 2 are 'mobile.o2.co.uk' and 'wap.o2.co.uk' but using these two also client is not able to make Http connection. Is there any way of free unlimited internet connectivity in third party applications? I am not having a clear understanding of APN settings so kindly bear with me. I am using OS 4.5

Eargerly waiting for reply.

Welcome to the confusing world of network transports on BlackBerry! You will want to start with the article Connecting your BlackBerry - http and socket connections to the world.