If it's alway 2TB of completly new data, I would say, check for a real 1GB fiber internet link (commercial). However, it might not be in your budget. (not to insult)...
That said, if only a ''small'' amount of the 2TB change's from day to day, I would only transfer the data that differ from the full 2TB.
rsync would do a great job for that. There are ...
If you do not have the full environment to setup a webserver and such, you can always use:
It has restart/retry capabilities and can be run on a number of services.
Another tool I've used to transfer from London to New York :
Well, your queston lacks certain important information:
Can the file(s) change between adjacent attempts at transferring them?
What platform the server and the client run on?
Still, a couple of options:
Plain old HTTP supports download resumption — via the Range field in the request header.
So if you have a server supporting that (actually any production ...
If you don't have a dhcp server and you use the router and APs to serve dhcp, you can give different ranges of ips for the given APs you don't want to access the internet from, and then with iptables block traffic from those ips. So you don't have to create a new subnet and they will be able to communicate between them too.
Using lftp I was able to push my connection to its full capacity (900Mbps), you need something like this - lftp -e 'mirror --parallel=10 --use-pget-n=10 /var/vtemp /var/vtemp' sftp://root@XX.XX.XX.XX. The only problem I faced was that throughput degraded after running for a few hours.