enough
From the router point of view, a maximum of 254 terminals can be connected, the router has an IP, generally 192.168.1.1 or 192.168.0.1, the range of C segment is 001 ~ 255,001 must be occupied by the router itself, so in theory, there are 254 IP remaining.
The actual speed of 100M is about 10M per second, 10M is divided into 100 about the speed of each device at the same time is 100kb, just simple browsing web applications, 100 devices (can be networked hardware counts as a device) is no problem, if there are external server applications, data transmission, will also take up a lot of bandwidth. Generally speaking, properly managed, with more than 50 units is no problem.
That's enough under normal circumstances. In the enterprise, the enterprise Intranet is generally used to transfer data, because there are a lot of confidential data in the enterprise, which can not appear on the Internet, a lot of internal data is stored in the internal database, and these servers are not connected to the external network.
Enterprises generally use the Internet to set up a website to visit, the amount of data is not too high. 100 megabits is sufficient for use.