Iphone

Question: I would develop an application that may communicate two devices using Rs232. I will connect them to a GPRS modem. I found a service that offers IP non dynamic, I will use what they call a corpotarive APN that may allow me to get an IP that will not change.

My question is this: I start my application sending AT commands to get the modem connected to GPRS, but after that how would I use the IP to connect to the other modem, would it be using AT commands. I got confuse because I do not get the idea on how to develop an application that use IP if the connection to the network is done by a modem.

I would appreciate any comment

Iphone

>>I start my application sending AT commands to get the modem connected to GPRS,

This is not an easy task...... It depends upon your modem's model and make. For most of GPRS modems this is not possible.....
The alternative is to use Dial-Up service of Windows to dial the GPRS connection. This is explained completely in the following question where I helped another asker. It also tells you how to transfer data/file from one system to the other system....

General Packet Radio Service (GPRS): GPRS tranfering and reciving file