The minimum contracted payment owed by a customer. In NNN Colocation contracts, in addition to Base Rent, the customer is responsible for paying certain pro rata costs associated with operation of the data center and the building within which it operates; this would include all expenses such as property taxes, insurance premiums, repairs, utilities, maintenance, security, and direct power consumption.  In Modified Gross Colocation contracts, the Base Rent will typically include all such expenses, with the exception of the power consumed by the customer's IT equipment and its pro rata share of power required to cool its IT equipment. In Gross Colocation contracts, the Base Rent is the absolute total payment to cover every expense related to the customer's colocation requirement.