Question : Amount of bandwidth needed

I want to set up a connection to my remote office in another state.  

My choices are:

A) A dedicated circuit
B) A site-to -site VPN

I need to replicate my file server (real time changes), my Active Directory infrastructure, and Exchange 2007 using CCR.

Does anybody know how much bandwidth I will need?   Is there a formula to calculate the amount of needed bandwidth?

I am looking into a T1 dedicated circuit or a 6 Mbps connection to the Internet on both ends to support a site-to site tunnel.

Answer : Amount of bandwidth needed

>It's going to be a fractional T3 so the issues you outline should not be a concern for me.   I believe the upload/download speeds of a T3 are the same as a T1.
Actually, a T3 is even more robust and reliable than a T1. T3 = 45Mb capacity, metered to 6Mb. With such a wide pipeline, serialization delay almost disappears. That's a very good thing for performance.

For 40-50 Gb per day, I'd say that would saturate a T1 for most of the day and not much else would get accomplished.
The Shunra VE tool would be very good for you to run "what if" scenarios.
http://www.shunra.com/content.aspx?pageId=5