Rack Mount Wire Management

Regarding the rack mount wire management, many new beginners have raised questions, with some inquiring about specific methods. Over time, due to personnel changes and network adjustments in daily work, our cabinets or network racks can become very messy. The placement of equipment in the network rack, the introduction of power cables, and the management of network and communication wires are very troublesome issues. This increases the difficulty of rack mount wire management and can also affect network quality.

So how can we organize the network racks and server cabinets to make it orderly?

This project targets the very messy wiring in the data center of a specific tumor hospital, where equipment is temporarily stacked everywhere, seriously affecting normal business use and making daily maintenance difficult. The wiring will be rectified to create a neat, aesthetically pleasing, and easily maintainable computer room.
The current state of the computer room is depicted in the image below.

It can be seen that it is indeed very messy, and it is not surprising that network problems occur. So how can we manage the wires?

The network cables should be organized according to the network topology and existing equipment conditions:

1. In principle, power cables and network cables in the cabinet should be organized separately;

2. Equipment should be placed appropriately to avoid mutual squeezing, being too high or too low, and being too close to each other;

3. If there are too many devices in the cabinet, they should be numbered;

4. Each cable should be labeled at an appropriate position to indicate its source;

5. Different types of connections (such as general network connection cables, crossover cables, dedicated lines, etc.) should have different identification methods;

6. Network cables should be arranged according to room numbers rather than individuals.
In summary, the layout should be clear, the wire sequence should be orderly, labels should be clear, and maintenance should be easy, especially the rational use of labels is very important.

First, notify users to mark wire labels and organize the rack cabinet without affecting their normal work. Then, based on the network topology, existing equipment conditions, number of users, user groups, and other factors, draw the internal wiring diagram and equipment location diagram of the cabinet.
Next, prepare the necessary materials: network patch cables, fiber patch cables, power cables, label paper, marker pens, and plastic cable ties. 

 

We need to do the following three things ourselves: First, use the screws and nuts that come with the frame to tighten the fixing frame; second, lay the cabinet down and install the movable wheels; third, adjust and add baffles on the fixing frame according to the equipment's position.

Group the network cables, with the number of groups usually less than or equal to the number of wire management racks behind the cabinet. Bundle all the equipment's power cables together, insert the plugs from the rear cable holes, and then find their respective devices through a separate wire management rack.

Adjust the baffles in the cabinet to a suitable position so that the administrator can see the operation of all devices without opening the cabinet door, and add baffles appropriately according to the number and size of the devices. Pay attention to leaving some space between the baffles. Place all the switching and routing devices used in the cabinet according to the pre-drawn diagram.

Once all network cables are connected, each one must be labeled. Wrap the prepared labels around the network cables and mark them with a pen (usually indicating the room number or purpose), ensuring that the labels are clear and easy to understand. Crossover cables can be distinguished from general network cables by using labels of different colors. If there are too many devices, they should be classified and numbered, and labels should be attached to the devices.

After confirming that everything is correct, power on and conduct a network connectivity test to ensure normal user work-this is the most important.
 

Update the documentation for this cabinet organization. Redraw the equipment layout diagram and network cable connection diagram. The diagram should indicate the device numbers and network cable labels for future maintenance reference. It is recommended to include the username as an item in the diagram, and finally note the date and the person who organized the wires.

 

An important part of cabinet organization is cabinet wire management. There are three common wire management processes:

 

This is a relatively old wiring style, and its traces can still be seen sometimes. It adopts the artistic image of "Cave Waterfall" directly hanging the twisted pair cables from the patch panel modules, creating a beautiful sense of hierarchy when distributed neatly (24-48 twisted pairs per layer).

 

The advantage of this style is that it reduces labor for network cable management, but there are many disadvantages.

For example:

(1) It is easy to disrupt the arrangement when installing network equipment, and it may even be difficult to install the network equipment in place;

(2) The weight of each twisted pair becomes a pulling force acting on the back of the keystone module. If the twisted pairs are not tied before the termination point, this pulling force may separate the keystone jack from the twisted pairs after months or years, causing disconnection faults;

(3) If a keystone module in the patch panel needs to be re-terminated, the maintenance personnel can only work inside the "water curtain," sometimes wearing dozens of twisted pairs, and because there is no light source in both directions, it is difficult to see during termination.

 

Reverse wire management is performed after the patch panel modules are terminated and tested. The method is to manage the wires from the module to the outside of the cabinet, while also managing the cables in the cable bridge.
The advantage of this method is that after testing, there is no need to re-manage the cables due to a failed twisted pair test, but the disadvantage is that since both ends (the inlet and the patch panel) are fixed, there will inevitably be a lot of messy cables somewhere in the computer room (usually at the bottom of the cabinet). Reverse wire management is generally done manually, relying on the eyes and hands to complete the wire management. The advantage of reverse wire management is that the test has been completed, so there is no need to worry about the length of the cables at the back of the cabinet. The disadvantage is that since both ends of the cables are fixed, there will be a lot of crossovers between the cables, making it very laborious to organize them neatly, and there will inevitably be a place where the twisted pairs are messy between the two fixed ends, often under the floor (when entering from below) or above the ceiling (when entering from above).

Forward wire management is performed before the patch panel modules are terminated. It starts from the inlet of the computer room, organizing the cables section by section until the patch panel modules. After wire management, termination and testing are performed.
 

From the inlet of the computer room (or the network area of the computer room) to the horizontal twisted pairs of the patch panel cabinet, forming bundles of horizontal twisted pairs in units of each 16/24/32/48-port patch panel, with all twisted pairs in each bundle parallel (the crosstalk between twisted pairs in short distances will not affect the overall performance, because most of each twisted pair is laid in the bridge and conduit, this part is loose and not parallel), and all bundles are parallel; after verification, they are fixed on the cable tray behind the module or passed through the module holes of the patch panel.

 

The advantage of forward wire management is that it ensures that the cables in the computer room are neat at every point, and there will be no cable crossovers. The disadvantage is that if the cable is damaged during installation, a failed test will necessitate re-cable management. Therefore, the premise of forward wire management is to have sufficient confidence in the quality of the cables and the cable pulling.

 

Based on this, decide where to place the patch panel, and then calculate how long the network cables need to be to install the patch panel on the cabinet, taking into account the distance from the outside to the cabinet, to facilitate the overall wire management later. If the cables are placed too long in the cabinet, it can cause an unsightly situation, and later wire management will be troublesome, requiring constant pulling back to organize the cables neatly and beautifully.

Secondly, consider how the cables will run after entering the cabinet from the top or bottom.Try not to bend or bypass things, and run along the cabinet as much as possible. Consider that the direction of the cable run should not affect the entry of future network equipment, which requires the staff to have some foresight.

 

Cut according to the length calculated in the first step. Trim the excess, ensuring consistency to maintain a neat appearance, and leave some redundancy compared to the calculation, preferably ten to fifteen centimeters, including the length of the stripped jacket and the patch panel. At this time, there is no need to put the cables into the cabinet from the outside, because putting them in at this time will make wire management difficult.

Start tying the cables with cable ties where the roots of the cables begin to be exposed. Secure most of the network cables as needed, and then proceed to use the patch panel for wire management. The method of using the patch panel is to pass the cables through the back of the patch panel one by one according to a convention, and tie two consecutive network cables together with cable ties on the back of the patch panel. Each two ties should have a misalignment, that is, do not tie too many side by side, and it is best to have some distance between each two ties. After tying two consecutive cables, start tying six network cables together, and on average, re-tie every half meter, paying attention to neatness when tying, and avoiding haphazard bundling to maintain a neat and organized appearance.

 

Use the wire management board to move down continuously, and also tie the back of the wire management board with cable ties (half a meter per tie). The last six-tie position is about one meter away from the end of the cable. After tying, start tying two cables nearby, of course, still in order. After tying each two, use the same method to tie again about half a meter down, which is beneficial for the next step of installing the patch panel.

Next is the step of installing the patch panel. Since the above work has been completed, the cables are already very clear. Route the cables outside the cabinet and place them on a workbench. Begin the crimping process in groups of three, following the pre-arranged positions to minimize errors. The specific process steps of crimping will not be repeated here.

 

If the test passes, install it on the cabinet. If any points fail, carefully check the contact between the network cable and the module and the cable sequence, and aim to achieve a successful test on the first attempt. After all the keystone modules are crimped and tested, install them on the cabinet. After installation, tie the network cables according to the original plan to achieve neatness, beauty, and straightness. Document the connectivity of each point. If a point fails, document it in the remarks log.