The following are recommended methodologies for all Local Exchange Carriers (LECs) to provide for timely notification to the Industry of changes in their access network architecture. These recommended methodologies should apply to any access network reconfiguration that affects Access Customer routing or rating of calls such as: Tandem homing arrangements; Switch reconfigurations affecting rating or routing; New or changed NXX, including new and existing NXXs designated as portable; New or changed NPA; Changes in rate centers.