For most setups, cables with 12, 24, or 48 cores are common choices, ensuring compatibility with modern equipment and ease of management. IBDN standard suggests using 12-core cables for communication rooms within buildings and 24-core cables for main distribution rooms, which can serve as a. According to the IBDN standard, we generally recommend using 12 cores for the communication room in each building, and 24 cores for the building room. Of course, this is a general situation, and specific words may consider according to the following criteria. Number of wiring points and switches. If you have multiple Ethernet switches that need to be connected over long distances, fiber is obviously a preferred choice.