What is the accepted usage of unlimited bandwidth with the Data center network?

The accepted usage of unlimited bandwidth on the datacenter IPs is defined as up to 100GB per IP per Month.
The transfer amount is cumulative across IPs, so 100GB x the number of IPs.
Ex: You have two IPs and therefore 200GB that can be used with any IP. 

This definition depends on your chosen price plan and the amount of allocated IPs.
Bright Data reserves the right to periodically review and change the usage levels of unlimited bandwidth to ensure it is not being overused.

In cases where excessive usage of unlimited bandwidth is detected, you will be informed via email so that you should adjust the amount of allocated IPs in your zone to fit your traffic volume or move your plan to Pay per IP