What is the CCU of the default Unity Networking?

Is it unlimited? I can’t seem to find an answer anywhere.

Like how Photon’s CCU is 20 for the Free, is there a limit to the CCU of Unity Free?

There is theroreticaly no CCU limit in Unity’s networking, and during internal load tests we’ve managed to connect over a thousand dummy clients.
In practice, however, Unity has a bandwidth limit of roughly 110mb/s, and we’ve seen a peak of about 400K RPC/s with a solid and stable 100K RPC/s build.
However, the CPU/RAM resources required to handle this many players along with any meaningful game logic will probably be a harsher limit.