What is a closed user group?
A closed user group (CUG) is a group configuration that restricts access beyond the defined group of group members. This type of setup can be useful in digital and telecommunications service designs.
Although CUG can be used to refer to an exclusive service that is intentionally closed for the benefit of its members, most definitions include restrictions that are applied to the members themselves. In the telecommunications industry, for example, CUG members can only make and receive calls within the user group. Service providers use a CUG to add value to the cost and to present additional options to customers.