Just checking .. expected behavior of Membership on Multisite?

My apologies if this in the documentation or usage notes, but I would like to know the following while I am planning out my network structure. For the purposes of this exercise, assume there is only one paid membership type.

1. If Membership is network activated, does the access level and subscription plan apply automatically to all sub-sites? Will a member of one site have access to the protected content of the other sites?

2. If Membership is activated on site by site basis, does that mean that each site becomes part of a single “umbrella” membership network, or does it mean each site can create its own memberships with access levels and plans unique to that site?