Thank you for this information. The mobile IP address does in fact begin with a 10. I have spoken with the technical support staff from AT&T, as they are the ISP we have a data plan with. The concept of a mobile initiated vs. mobile terminated IP address did not register with them. I will initiate another tech service request. Do you have any line of sight on whether or not AT&T is capable of providing a data plan which will work? Cheers.