Cable trays / ladder rack
Metal channels that run above or under your racks to carry the long permanent cables. They keep bundles off the floor, keep airflow clean, and make adding a new run a five-minute job instead of a half-day rebuild.
Without a tray, every new cable is a one-off snake across the floor that the next cable has to fight past. With trays in place you have planned highways: drop a cable onto the tray, follow the channel to the destination rack, and you are done. The first tray you lay is the moment your cabling stops being a pile and starts being infrastructure.
Detailed explanation
Ladder / basket / wire-mesh / J-hook / vertical-riser runs. Each is a routed path carrying anchors the cable planner uses to commit segments. The planner resolves waypoints into typed anchors, so a tray run is a deterministic channel rather than a free-air guess.
Tray runs carry sag-suppression: SLOT↔SLOT same-column and TRAY↔TRAY same-tray segments skip the air sag, so a supported run reads taut instead of drooping. Bend-radius enforcement (validate_bend_radius_tray_run) owns tray / J-hook / point chains in world space, so a route that would kink the cable around a tray corner is rejected before it commits.