Cat3 cable terminates with RJ11 connectors at the telephone end. On the distribution side, it is punched down on 66-block or 110-block cross-connects, which remain standard in commercial telecom rooms throughout DFW. If your building still has Cat3 voice cabling and you’re moving to a VoIP or cloud phone system, Just Cabling can assess whether your existing infrastructure can be repurposed or needs to be replaced with Cat5e.