47 CFR § 51.331 - Notice of network changes: Timing of notice.
(a) An incumbent LEC shall give public notice of planned changes at the make/buy point, as defined in paragraph (b) of this section, but at least 12 months before implementation, except as provided below:
(1) If the changes can be implemented within twelve months of the make/buy point, public notice must be given at the make/buy point, but at least six months before implementation.
(b) For purposes of this section, the make/buy point is the time at which an incumbent LEC decides to make for itself, or to procure from another entity, any product the design of which affects or relies on a new or changed network interface. If an incumbent LEC's planned changes do not require it to make or to procure a product, then the make/buy point is the point at which the incumbent LEC makes a definite decision to implement a network change.
(1) For purposes of this section, a product is any hardware r software for use in an incumbent LEC's network or in conjunction with its facilities that, when installed, could affect the compatibility of an interconnected service provider's network, facilities or services with an incumbent LEC's existing telephone network, facilities or services, or with any of an incumbent carrier's services or capabilities.
(2) For purposes of this section a definite decision is reached when an incumbent LEC determines that the change is warranted, establishes a timetable for anticipated implementation, and takes any action toward implementation of the change within its network.