Waterfall design
This is a relatively ancient network cabinet wiring design, and sometimes its traces can still be seen. It adopts the artistic image of "Huaguo Mountain Water Curtain Cave", where twisted pair cables are hung directly from the modules of the distribution frame, creating a beautiful sense of hierarchy when distributed neatly (24-48 twisted pair cables per layer).
The advantage of this design is that it saves manual line management, but there are many disadvantages, such as: it is easy to damage the design when installing network equipment, and even difficult to install the network equipment in place; The weight of each twisted pair cable is converted into tension, which acts on the rear side of the module. If the twisted pair cable is not tied before the termination point, this tension may separate the module from the twisted pair cable months or years later, causing a wire breakage fault; If a module in the distribution frame needs to be re terminated, maintenance personnel can only enter the "water curtain" for construction, sometimes wearing dozens of twisted pair wires, and due to the lack of light sources in both directions, it is difficult to see the termination clearly.
Reverse reasoning line
Reverse wiring is performed after the module termination of the distribution frame is completed and tested, followed by cabinet wiring. The method is to start wiring from the module to the outside of the cabinet, while also wiring inside the cable tray. The advantage of doing this is that after testing, the wiring will not be re routed due to a twisted pair cable failing the test. However, the disadvantage is that since both ends (inlet and distribution frame) are already fixed, there will inevitably be a large number of tangled wires in a certain part of the computer room (usually at the bottom of the cabinet).
Reverse alignment is generally done manually, relying on the naked eye and hands to complete the alignment.
The advantage of reverse wiring is that the testing has already been completed, so there is no need to worry about the cable length behind the cabinet. The disadvantage is that because the two ends of the cable are already fixed, there will be a large number of crossings between the cables, which is very difficult to tidy up. Moreover, there must be a scattered twisted pair between the two fixed ends, which is often located under the floor (when the cable enters below) or on the ceiling (when the cable enters above).
Positive Line
Forward wiring is done before terminating the distribution frame. It starts from the inlet of the computer room and organizes the cables section by section until they reach the module of the distribution frame. Perform termination and testing after wiring.
The goal of forward routing is to form a bundle of horizontal twisted pair cables from the inlet of the computer room (or network area of the computer room) to the distribution cabinet, with each 16/24/32/48 port distribution frame as the unit, forming a bundle of horizontal twisted pair cables. All twisted pair cables in each bundle are parallel (the crosstalk between short distance twisted pair cables will not affect the overall performance, because most of each twisted pair cable is laid in the cable tray and conduit, which is scattered and non parallel), and all harnesses are parallel to each other; After each twisted pair cable is bent in the cabinet, it is laid to the back of each distribution frame, and the entire process still maintains the parallelism of the twisted pair cables in the harness. Pull out the twisted pair corresponding to each module from the bottom of the wiring harness at the back of each module, verify that it is correct, and fix it on the cable tray behind the module or thread it into the module hole of the distribution frame.
The advantage of forward routing is that it can ensure that the cables in the computer room are neat at every point and there will be no cable crossings. The disadvantage is that if the cable itself is damaged during threading, failing the test will result in rewiring. Therefore, the premise of positive wiring is to have sufficient confidence in the quality of cables and threading.
The advantage of forward wiring is that it is neat and parallel from the incoming line port to the distribution frame in the computer room (network area or weak current room of the host room), which is very beautiful. The disadvantage is that construction personnel need to have a full grasp of their own construction quality, and can only carry out forward alignment construction on the basis that they will not be re terminated.