2011-01-11 04:31 PM
Yes. It's called a calculator. In all seriousness, your assigned NetApp Systems Engineer should have access to a utility called "Quick Bandwidth Wizard" in his Synergy 3.0 tool. This individual can assist you. In the meantime, you can take a swag at this calculation:
( 7 GB of changed blocks / 8 hour backup window ) = 917.5 MB/hr / 60 minutes = 15.3 MB/minute / 60 seconds = 254.8 KB/sec. So you would need a WAN link capable of sustaining 255 Kilobytes (2040 kilobits) per second for 8 hours. So if your backup window was only 8 hours, a T1 link capable of 1.544 megabits per second ( 193 Kilobytes per sec) wouldn't quite cut it.
Here is a handy tool you can use to determine the type of WAN link you'd need.