Interconnection Agreement Database: Select company type to begin search. CLEC ILEC CLEC - Competitive Local Exchange Carrier ILEC - Incumbent Local Exchange Carrier Thank you for visiting the NPSC's Interconnection Agreement (ICA) Database. Should any problems arise, please contact the NPSC Webmaster Best viewed with Netscape or Internet Exporer 4.0 and above at screen resolution 800x600 and above.