CfB can offer a minimum bound on bandwidth required for 1000 TPS (1 MBS) but can't say how many NXT service nodes that can handle the full blockchain are required.
I forgot about a very important detail. 1000 tps @ 1 Mbps assumes that we use
binary protocol. Now all data in protocol is encoded in
JSON, this adds 3x-5x overhead.
We have to migrate to binary protocol before switching TF on.