Text Size
Data volume (MB)
Time Window (hours)
Compression Ratio
WAN Bandwidth (Mbps)
Latency (ms)
TCP window size (KB)
TCP session throughput (Mbps)
TCP Sessions required

Bandwidth requirements calculation
In order to estimate the bandwidth needed the following calculation was used:

T = (d / t) * (8 bits/Byte + 2 bits/Byte overhead) * (1 hour / 3600)

T = Sustained WAN Bandwidth required to transfer data in Mbps
d = Amount of data to be transferred in Mbytes
t = Maximum amount of time allotted for transfer in hours

When I convert bits to bytes, I use 10 bits per byte instead of 8, to account for some packet overhead in transmittion.
A 1500 byte ethernet frame has 40 bytes of TCP/IP and ethernet headers, so I was trying to account for that.
This would account for some of the IP header overhead. Not completely scientific but better.

TCP Throughput calculation
In order to estimate the throughput, of a single TCP flow or session, the following calculation was used:

T = (w / l)

T = Maximum TCP session throughput in Bps
w = TCP stack window size in bytes
l = Roundtrip network latency in seconds