3G Modem interfacing

Hi Folks,

I am looking to add ip conectivity to my arduino and i would like some help.

First, can I get a serial port over the internet? I used to use a circuit switched gsm data call years ago, but now only gprs is available

Second, regarding the usb host shield, can it work with 3G dongles?

First, can I get a serial port over the internet?

No.

Second, regarding the usb host shield, can it work with 3G dongles?

Once you write the driver, yes.

In this case what can I use to transfer data, say, between two microcontrollers via GPRS?

The idea is to have a always on connection and the device can be remote acessed. A serial port would seem the most logical thing when CSD was availabale, what alternatives do i have now?

Regarding the 3G dongle, would they be found as an ACM driver? Apparently the card can interface directly with one, but I dont know exactly what does the micircontroller see on its side?

The idea is to have a always on connection

That's not what GPRS, or any client/server architecture, was designed for.

What do you mean? Isnt GPRS used to create a connection that is always on and ready to be used when required?