47 CFR § 51.317 - Standards for requiring the unbundling of network elements.
(a) Proprietary network elements. A network element shall be considered to be proprietary if an incumbent LEC can demonstrate that it has invested resources to develop proprietary information or functionalities that are protected by patent, copyright or trade secret law. The Commission shall undertake the following analysis to determine whether a proprietary network element should be made available for purposes of section 251(c)(3) of the Act:
(1) Determine whether access to the proprietary network element is “necessary.” A network element is “necessary” if, taking into consideration the availability of alternative elements outside the incumbent LEC's network, including self-provisioning by a requesting telecommunications carrier or acquiring an alternative from a third-party supplier, lack of access to the network element precludes a requesting telecommunications carrier from providing the services that it seeks to offer. If access is “necessary,” the Commission may require the unbundling of such proprietary network element.
(2) In the event that such access is not “necessary,” the Commission may require unbundling if it is determined that:
(i) The incumbent LEC has implemented only a minor modification to the network element in order to qualify for proprietary treatment;
(ii) The information or functionality that is proprietary in nature does not differentiate the incumbent LEC's services from the requesting telecommunications carrier's services; or
(iii) Lack of access to such element would jeopardize the goals of the Act.
(b) Non-proprietary network elements. The Commission shall determine whether a non-proprietary network element should be made available for purposes of section 251(c)(3) of the Act by analyzing, at a minimum, whether lack of access to a non-proprietary network element “impairs” a requesting carrier's ability to provide the service it seeks to offer. A requesting carrier's ability to provide service is “impaired” if, taking into consideration the availability of alternative elements outside the incumbent LEC's network, including elements self-provisioned by the requesting carrier or acquired as an alternative from a third-party supplier, lack of access to that element poses a barrier or barriers to entry, including operational and economic barriers, that are likely to make entry into a market by a reasonably efficient competitor uneconomic.