Nowadays, enterprise information degree more and more high, the capacity of the single file is more and more big, the data center supported by the application is more and more widely, these all make the data transfer and storage in the center of a growing amount of information. Basis within the data center network design and operation, have to cope with this challenge, in satisfy the business enterprise of high rate, high bandwidth transmission at the same time, also want to meet the high performance and scalability, and reasonable control the budget.
Wiring system planning
Cost is always decided to data center design and construction of the key factors. Any enterprise all hope through the low cost of ownership to support as much as possible the most long-term business development. Although the cost of wiring system accounts for about 5% of the total cost in the data center, but it is one of the longest service life network elements. Usually, wiring system needs to be up to 10 ~ 15 years or even longer life cycle. , and at the same time, the network equipment is usually 3 ~ 5 years would need to be replaced. The conclusion is that the wiring system planning must can support 2 ~ 3 generation of active equipment upgrades. This relationship not only to the user the overall cost savings, will be conducive to save more energy and resources available.
Second, is the important index to measure the reliability of the network uptime, refers to the amount of time users obtain important business service. 70% of the service interruption is due to the data center wiring system maintenance of mobile, add, and change. Therefore, IT managers make decisions on wiring system will directly affect the minimizing network interruption time and the ability to maximize business continuity. If has been clear about the requirement for normal operation time and determine the related equipment, can be estimated bandwidth, power and cooling load, and can determine the space required for the data center.
The choice of wiring medium
At present, most of the overall design in a data center to support data transfer rate of 1 gb/s. General consensus in the industry is, however, to 10 gb/s transmission rate will advance. This evolution, the first will occur on a storage area network (SAN), and the application of some special environment. To be sure, in 3 ~ 5 years, support 10 gb/s transmission link will become the mainstream of the data center. Based on the situation, ISO and TIA about fiber optic and copper support 10 gb Ethernet transmission standard.
When choosing wiring system transmission medium, need in bandwidth, flexibility, scalability and cost elements such as between seek a balance. Fully considering the development of the application, choose the most appropriate, proactive transmission medium to be the most wise choice. In short, if need to build a scalable and life cycle longer wiring system, ideal choice is to install cable support high bandwidth applications, change the wiring by demanding higher risk.
Next, by comparing the advantages and disadvantages of common wiring media, to help the reader to make a choice.
1. The optical fiber system
Optical fiber is the best medium for information transmission, not only has copper in long distance, high speed transmission system incomparable advantages, at the same time, with copper manufacturing limited by raw materials - copper this rare resource is different, the manufacture of the fiber without being limited by the raw materials. In addition, compared with copper cable, fiber optic cable size smaller, when the network also need not constrained by the number of links within the connector, and do not need to consider the problem of which will be affected by electromagnetic interference. With the trend of "light into the copper retreat", optical fiber system in the data center will play an increasingly important role.
Still expensive, because the price of fiber optic port equipment, several times in the same application copper equipment, which become the optical fiber system are not completely replace the main reason of the copper wire systems. Second, the optical fiber installation need to use special tools for professional practitioners, construction cost and requirements are relatively high. In addition, in the face of emerging and high-profile PoE Ethernet power supply technology, optical fiber system is unable to support.
For optical fiber system within the data center, the general consensus in the industry is OM3 is recommended for the optimization of optical fiber laser system. This system can make use of VCSEL (vertical surface laser) light source in the 850 - nm wavelength support, 10 gb/s transmission distance can be up to 300 meters. In terms of upgrade, some manufacturers to surpass 10 gb/s standard, using coarse wavelength division multiplexing technology transfer 40 gb/s.
2. The copper system
Although compared with optical system, copper system on the transmission distance and number of channel connector is restricted, but copper system is the most familiar with all the design, installation and use of personnel. It can be implemented by means of low cost, high speed application from gbase - 10/100/1000 base-t to 10 T, copper system can be well supported. In addition, the shielding system can support PoE application, at the same time of data transmission signal power supply for remote devices.
When in 2005 issued 942 TIA standards, 6 class a standard is not yet mature. Considering the market situation at that time, in this standard, it is recommended to use cable 6 class or above level. Today, it seems, 6 a class is the most economical of the implementation of the 10 gb/s transmission requirements link configuration mode, the system USES two times higher than 6 classes do not cost supply 10 times of transmission capacity, so the cost of each Gbps are much lower. Although 6 class can also support in short 10 gb/s, but its ability to suppress noise and transmission performance is far better than 6 a.
Although the existing 10 g on market copper port network equipment is expensive, but with the mass production of equipment manufacturers, the market matures, the price will naturally reduce, like at the beginning of gigabit port equipment. Notable is, due to the requirements of the power is very high, 10 g transmission power consumption per port to the earlier transceiver even reached 10 to 15 watts, so in 10 gbase -t standard stipulated in the "low power short distance transmission mode", reducing power consumption per port to 4 watts. Importantly, only 6 or higher class a type of cable can support this pattern within 30 meters distance.
3. The screen or a shield
It is understood that the system has good resistance to electromagnetic interference shielding and the ability to prevent information leakage. To support Wan Zhao transmission 6 a kind of shielding system, can need not consider outside crosstalk test problems, it will save a lot of testing time. At present, the domestic most users consider using shielding systems because of information security. In addition, the shielding system can support higher bandwidth applications, a maximum of 1.2 GHz.
However, shielding wiring system development also has its limitations. First, shielding system currently worldwide acceptance is low, may only account for 5% of the entire copper wiring system market share. This means that the design, installation personnel are relative to its strange, need further training. Because of the shielding system to ensure that the 360 - degree continuity shielding, shielding system must be properly installed and grounded, construction difficulty is high, long time consuming. In addition, because of the existence of metal protective layer using shielding systems support PoE Plus applications, the heat generated by the cable can't out, will produce certain interference in performance.
Investment protection wiring system
In addition to selecting the appropriate cable media type, how to manage and protect the wiring system, to ensure business continuity, prolong the lifecycle of the wiring system is very heavy
The following is a list of some of the key points:
Mixer label system
Label is the basis of the wiring system management, also is the basic element of the data center. A good label system will help the network management personnel to quickly find information, shorten the time of the move, add, and change. A good label for owners as well as increase the additional value, improve the aesthetic, still can make work more efficient, flexible and reliable.
Mixer path and space
Due to the data center is a high density of computing environment, in which there are a lot of cables. If at the beginning of the design is not reasonable path for these cables and spatial planning, with the operation of the data center and extension, cables will be out of control and crowded. Will ultimately affect the refrigeration capacity of the data center, and even can't maintain, had to redevelopment.
Ideal solution for: the reasonable use of limited space within the data center, on copper cable, optical cable and power cable well space and path planning, is the three types cable effective separation, easy to implement and maintain. While walking on line or down line choice, each have different advantages and disadvantages. Suggestion is the best long-term fixed cables, such as the overhead floor below go on the trunk and horizontal cable line, and will jump line (copper and fiber optic jumper wire) using go above the frame line.
Different cable, the wire diameter is different. Cables must be taken into account in design line path, the path to fill rates. Advice, when the design path fill rate for 35% ~ 40%.
Pieces of cabinets and racks
In order to achieve good cable management, reduce the maintenance personnel move, add, and change the wiring system of time, within the data center should be chosen with cable management design of cabinets and chassis products. In racks and racks to consider vertical and horizontal cable manager and redundancy of the length of the cable is received, maintain the cable bending radius at the same time, let the cable more orderly; Avoid the cable of the winding and accumulation to block the flow of hot and cold air on racks and racks, make active effectively realize ventilation cooling equipment.
Pieces of intelligent management system in the physical
Intelligent management system to help the physical network management personnel to understand the network connectivity, through real-time monitoring connection status, can quickly identify any network interruption, and promptly report to the system administrator. This helps to quickly troubleshoot and security threats, minimize downtime.
In addition, the intelligent management system database records system and the physical movement and configuration changes of the physical assets. This information can be used to meet industry regulations reporting requirements and establish customer data center service level agreements (SLAs), and avoid the manual analysis table possible human error.