27 13 00 Communications Backbone Cabling
27 13 23 Communications Optical Fiber Backbone Cabling
27 13 13Communications Copper Backbone Cabling27 13 13.13Communications Copper Cable Splicing and Terminations27 13 23Communications Optical Fiber Backbone Cabling27 13 23.13Communications Optical Fiber Splicing and Terminations27 13 33Communications Coaxial Backbone Cabling27 13 33.13Communications Coaxial Splicing and Terminations27 13 43Communications Services Cabling27 13 43.13Dialtone Services Cabling27 13 43.23T1 Services Cabling27 13 43.33DSL Services Cabling27 13 43.43Cable Services Cabling27 13 43.53Satellite Services Cabling