Data center cabling system components and examples of different scales

Data Center Cabling System Composition

At present, the general integrated cabling standards that can be referred to for data center construction mainly include: national standard GB50174-2008, international standard ISO/IEC 24764-2010, European standard EN 50173.5/1-2007 and American standard TIA 942-2005.

The foreign standards listed above have slightly different contents in naming and topological structures of the components of the data center integrated cabling system, but they are consistent in principle. The terminology of the European standard is completely consistent with that of the international standard. Since the national standard GB50174 does not make a clear definition of the composition of the data center cabling system, from the perspective of engineering design application, the domestic standard recommends the use of the content of the international standard.

In addition to the standards listed above, relevant integrated wiring standards should also be strictly implemented during the data center design process, such as the technical requirements of GB50311, GB50312, TIA568C, ISO/IEC11801, etc.

1 Data Center Cabling System Composition and Naming

Table 3.1.1 lists the correspondence between the terms defined in various standards for the composition of data center cabling systems, and uses this table to understand the topology diagram.

Table 3.1.1 Correspondence between wiring system components and names

2 Data Center Cabling System Composition

The data center cabling system includes computer room cabling and support space cabling. The following refers to the cabling topology diagrams defined by various standards.

(1) The wiring structure of the computer room in GB50174 standard is shown in Figure 3.1.1-1.

Figure 3.1.1-1 Schematic diagram of the installation position of the data center cabinet

GB50174 oversimplifies the architecture of the building data center cabling system, only stipulating that a main distribution frame be set up in the machine room and connected to the horizontal distribution frame (HD), collection point (CP) and information socket (TO) through cables. The above figure also only shows that the terminal cabinet can be CP or HD. The BD and HD distribution frames can be connected in a cross-connection manner to facilitate the management of wiring equipment. The terminology is also inconsistent with foreign standards. The revised GB50174 will be closer to the international standard.

(2) The wiring structure of the computer room in the ISO/IEC standard is shown in Figure 3.1.1-2 and Figure 3.1.1-3.

Figure 3.1.1-2 Data center cabling structure in ISO/IEC standards

In ISO/IEC 24764, the standard data center universal cabling architecture is described as the following structure diagram 3.1.1-3.

Figure 3.1.1-3 ISO/IEC 24764 architecture diagram

Redundancy considerations: Depending on the criticality of the data center business, the standard recommends that the redundancy of the general cabling system should be considered during design. By adding additional wiring areas, channel routing, and redundant cables, single point failures caused by wiring routing, fire, and external network interruptions can be effectively reduced. The redundancy of the general cabling system is shown in Figure 3.1.1-4 below:

Figure 3.1.1-4 General wiring system redundant routing architecture

Figure 3.1.1-4 above, from the perspective of a building complex, illustrates the interconnection between building wiring and computer room wiring systems in a data center consisting of multiple buildings. The main distribution frame of the computer room of a data center in a building can be interconnected with the building's horizontal distribution frame (FD) and external network interface through the network access distribution subsystem, thereby completing the interconnection between the data center wiring system and the building's general wiring system and the lines of external telecommunications operators. The wiring structure of the main distribution subsystem, regional distribution subsystem, and equipment wiring is formed inside the computer room.

(3) The wiring structure of the computer room in the TIA standard is shown in Figure 3.1.1-5.

Figure 3.1.1-5 Data center cabling structure in ISO/IEC standards

Figure 3.1.1-5 is developed based on a building. The wiring structure of the main wiring, intermediate wiring, horizontal wiring, regional wiring, and equipment wiring is formed inside the computer room of the data center in the building. The wiring rack in the main wiring area is connected to the wiring rack in the horizontal wiring area through the optional intermediate wiring area facilities or directly connected to the wiring rack in the equipment wiring area, and is interconnected with the building wiring system and the communication facilities of the telecommunications operator. In this way, the interconnection between the wiring system of the data center and the wiring system of the building and the lines of the external telecommunications operator is completed.

Examples of cabling systems for data centers of different sizes

Example of data center cabling system composition

Data centers of different sizes depend on the open business, network architecture and equipment capacity, as well as the layout and size of the computer room, and can include several or all of the subsystems of the data center cabling system. The scale and composition of a data center do not necessarily form a fixed combination, and a mixed mode of coexistence within it can also be adopted.

1 Small Data Center Composition

Small data centers often omit the backbone subsystem and concentrate horizontal cross-connections in one or several racks or cabinets in the main distribution area. All network devices are located in the main distribution area. The cross-connections connecting the external support space of the computer room and the telecommunications access network can also be concentrated in the main distribution area, which greatly simplifies the wiring topology. See Figure 3.1.3-1 below.

Figure 3.1.3-1 Composition of a small data center

2 Composition of Medium-Sized Data Centers

A medium-sized data center generally consists of an incoming line room, a telecommunications room, a main distribution area, and multiple horizontal distribution areas, occupying one room or one floor. A regional distribution area can be set between the horizontal distribution area and the equipment distribution area, see Figure 3.1.3-2 below.

Figure 3.1.3-2 Composition of a medium-sized data center

3 Composition of Large Data Centers

Large data centers occupy multiple floors or multiple rooms, and need to set up intermediate wiring areas on each floor or in each room as the aggregation center of the network. There are multiple telecommunications rooms to connect independent office and support spaces. For ultra-large data centers, it is necessary to add secondary incoming line rooms, and the cables can be directly connected to the intermediate wiring area or horizontal wiring area to solve the problem of excessive line length. See Figure 3.1.3-3 below.

Figure 3.1.3-3 Composition of large data centers

The efficiency of data center systems depends on optimized design. The design involves various aspects such as architecture, machinery, electrical and communications, and directly affects the rational use of space, equipment, personnel, water supply and energy consumption in the initial stage, but more importantly, it is energy saving and efficiency improvement in the operation stage.