The Most Detailed Data Center Cabling Method
May 13, 2023
Leave a message
Due to personnel changes and network adjustments in daily work, our server cabinets can become extremely messy over time. Placing equipment, routing power cables, and managing network and communication cables in the cabinets can be a challenging task. It increases the difficulty of management and can also impact network quality. So, how can we organize the server cabinets to make them orderly?
1. Current Situation of the Server Room
This project focuses on the chaotic cabling in a certain tumor hospital's data center, where equipment is temporarily stacked everywhere, severely affecting normal business operations and making it difficult to perform regular maintenance. The goal is to rectify the cabling to achieve a neat and visually appealing server room that is easy to maintain.
The following is the current state of the server room:
Chaotic cabling
Do you like this kind of cabling?
Anyone who can work in such an environment is truly incredible.
As can be seen, it is indeed messy, and it's no wonder there are network issues. So, how can we go about cabling?
2. Principles of Organizing the Cabinets
To organize the network cables, the following principles should be followed based on the network topology and existing equipment:
Power cables and network cables should be separated as much as possible.
Place the equipment appropriately to avoid compression, excessive height, or close proximity to each other.
If there are too many devices in the cabinet, they should be numbered for identification.
Indicate the source of each cable at the appropriate position.
Use different identification methods for different types of connections, such as general network cables, crossover cables, and dedicated lines.
Arrange the network cables based on room numbers rather than individuals.
In summary, the key is to have a clear layout, organized cable sequencing, clear labeling, and ease of maintenance. Proper use of labels is particularly important.
3. Cabinet Organization Steps
3.1 Preparations
First, notify the users to perform cable labeling and cabinet organization without affecting their normal work.
Then, based on the network topology, existing equipment, user quantity, user grouping, and other factors, create diagrams of cable routing and equipment positioning within the cabinet.
Next, prepare the necessary materials:
Ethernet patch cables, fiber optic patch cables, power cables, label paper, marker pen, and plastic zip ties.
3.2 Organizing the Cabinet
3.2.1 Cabinet Installation:
We need to perform the following three tasks:
First, use the screws and nuts provided with the cabinet to secure the mounting brackets tightly.
Second, tilt the cabinet and install the movable wheels.
Third, adjust and add partitions on the mounting brackets according to the equipment's positions.
3.2.2 Cable Organization:
Group the network cables, with the number of groups usually being smaller than or equal to the number of cable management panels at the rear of the cabinet. Bundle all power cables of the devices together and insert their plugs through the cable access hole at the rear, then route them to their respective devices using separate cable management panels.
3.2.3 Securing the Equipment:
Adjust the partitions within the cabinet to a suitable position, allowing the administrator to see the operation status of all devices without opening the cabinet door. Also, add partitions appropriately based on the number and size of the devices. Leave some gaps between the partitions. Place all used switches and routers inside the cabinet according to the pre-drawn diagram.
3.2.4 Labeling the Network Cables:
After connecting all the network cables, it is necessary to label each cable. Attach prepared labels directly to the cables and write relevant information (usually the room number or purpose) on them using a pen. The labeling should be clear and easy to understand. Differentiate crossover cables from regular cables by using instant labels of different colors. If there are too many devices, classify and number them, and label each device accordingly.
3.3 Post-Organizational Work
3.3.1 Network Testing:
After confirming everything is in order, power on the equipment and conduct network connectivity testing to ensure the normal operation of the users. This is the most crucial step.
3.3.2 Document Updates:
Update the documentation for the cabinet organization. Redraw the equipment layout and cable connection diagrams. Include device numbers and cable labels on the diagrams for reference during maintenance. It's preferable to include usernames in the diagrams and indicate the date and the person responsible for the cable management.
4. Cabinet Cable Management Techniques
An important aspect of cabinet organization is cabinet cable management, and there are three common cable management techniques:
4.1 Waterfall-style Layout
This is a relatively old-fashioned wiring layout style that can still be seen at times. It adopts the artistic image of "Waterfall in Flower and Fruit Mountain," where the twisted pair of cables hang directly down from the patch panel modules. When distributed neatly, it creates a beautiful layered effect (typically 24-48 pairs per layer).
The advantage of this style is saving labor in cable management, but it also has several disadvantages. For example:
(1) It is easy to disrupt the layout when installing network equipment, and it may even cause difficulties in properly installing the network equipment.
(2) The weight of each twisted pair cable becomes tension, exerting force on the backside of the module. If the twisted pair of cables are not bundled before the termination point, this tension may eventually separate the module from the cables after months or years, leading to cable breakage.
(3) If there is a need to re-terminate a module in the patch panel, maintenance personnel can only work within the "waterfall," sometimes having to handle dozens of twisted pair cables. Additionally, due to the lack of light sources from both directions, it can be difficult to see clearly during termination.
4.2 Reverse Cable Management
Reverse cable management involves organizing the cables in the cabinet after completing the termination of the patch panel modules and passing the testing phase. The method is to route the cables from the modules toward the outside of the cabinet while also managing the cables inside the cable tray.
The advantage of this approach is that cable management is done after testing, so there is no need to redo the cable management if a specific twisted pair cable fails the test. However, the downside is that due to the fixed ends (incoming and patch panel), there will inevitably be many messy cables at a certain location within the server room, typically at the bottom of the cabinet.
Reverse cable management is generally done manually, relying on visual inspection and manual handling.
The advantage of reverse cable management is that testing has been completed, eliminating concerns about the length of cables behind the cabinet. However, the downside is that due to the fixed ends of the cables, there will be a significant amount of crossing between the cables. Achieving neat organization is quite challenging, and there will always be a section of twisted pair cables scattered between the fixed ends, often located below the raised floor (for incoming cables) or above the ceiling (for outgoing cables).
4.3 Forward Cable Management
Forward cable management involves organizing the cables before termination in the patch panel. It starts from the entry point of the server room and systematically organizes the cables section by section until reaching the modules in the patch panel. Termination and testing are performed after cable management.
The goal of forward cable management is to create bundles of horizontal twisted pair cables from the entry point of the server room (or network area) to the patch panel cabinets. Each bundle corresponds to a 16/24/32/48-port patch panel. All cables within each bundle are parallel (the crosstalk generated by parallel twisted pairs over short distances does not affect overall performance, as most of the twisted pair cables are laid in the cable tray or conduit, and this part is loosely laid and not parallel). Once everything is verified, each bundle is fixed on a wire tray behind the module or inserted into the module slots in the patch panel.
The advantage of forward cable management is that it ensures that cables in the server room are organized neatly at every point and avoids cable crossing. However, the disadvantage is that if the cables are damaged during routing, failed testing will require redoing the cable management. Therefore, the prerequisite for forward cable management is to have sufficient confidence in the quality of the cables and routing.
5. Cabinet Cable Management Steps
5.1 First, measure the length of the cables needed.
Based on the determined position of the distribution frame and considering factors such as the distance from the outside to the cabinet, calculate the length of the network cables required for installing and organizing the distribution frame inside the cabinet. It is important to ensure that the cables placed inside the cabinet are not excessively long, as this can lead to an unsightly appearance and make cable management more difficult, requiring constant adjustment to achieve a neat and organized arrangement.
Next, consider how the cables will enter the cabinet from either the top or bottom, avoiding bending or crossing obstacles as much as possible. Whenever feasible, the cables should run along the cabinet to ensure the path does not hinder the installation of network equipment. This requires the personnel involved to have a certain level of foresight.
5.2 Trim the excess length.
Based on the measurements obtained in the first step, trim the cables accordingly. Remove any excess length while maintaining consistency to avoid affecting the aesthetics. It is advisable to leave a certain amount of redundancy, preferably around ten to fifteen centimeters, including the length required for attaching the distribution frame. At this stage, the cables should not yet be inserted into the cabinet, as it would complicate the cable management process.
5.3 Start cable management.
Start by securing the exposed portion of the cables near the cable ends using zip ties. After securing most of the network cables, begin organizing them using a patch panel. The patch panel should be used to thread each cable from the backside of the panel one by one, securing adjacent pairs of cables with zip ties. Each pair of zip ties should be slightly offset, avoiding excessive side-by-side bundling and maintaining some distance between them. Once the adjacent pairs are secured, proceed to bundle six cables together. It is recommended to reorganize the cables every half meter, ensuring they are neatly bundled. Care should be taken to avoid haphazard bundling that may give an untidy appearance.
5.4 Continue bundling.
Continuously move down the cable management panel, securing it with zip ties at the backside (one zip tie per half a meter). The final set of six bundled cables should be positioned approximately one meter away from the cable ends. After bundling, continue securing adjacent pairs in sequence, with each subsequent pair being secured again every half meter. This facilitates the next step of installing the cable racks.
5.5 Install the cable racks.
Now it is time to install the cable racks. After completing the previous steps, the cables should be well-organized. Place the cables outside the cabinet on a workbench, and a team of three people can begin terminating the cables. Following the predetermined positions, the termination process becomes less prone to errors. The specific details of the termination process are beyond the scope of this translation.
5.6 Test the terminated cable racks.
Test the connectivity of the terminated cable racks. If the test is successful, proceed with installing them into the cabinet. If any points fail the test, carefully examine the cable connections and wiring order. Strive to ensure that all points pass the test. Once all the modules have been successfully terminated and tested, proceed with installing them into the cabinet. After installation, bind the network cables according to the original plan, ensuring a neat and aesthetically pleasing arrangement. Keep a record of the connectivity of each point and any persistent failures should be noted in the log.
