Data Center San Area cabling Scenario

In the data center of Finance, Insurance, bond, government agency, etc., in order to ensure the speed of data calculation and the reliability of data storage and management, many core business applications are usually composed of high-performance server equipment such as standard or non-standard minicomputer, mainframe, etc. A separate SAN storage network is matched with these high-performance servers. In the implementation of this kind of equipment area wiring scheme, the wiring scheme implementation should focus on the reliability of wiring.  In addition, because the SAN network is an internal high-speed transmission network between devices, most of the current device I/O support Gigabit fiber transmission, fiber support million transmission distance and channel attenuation is inversely proportional to the wiring scheme at the same time to think about the smallest possible overall channel decay, based on the above thinking, talk about in San The way of thinking and implementation of regional wiring planning.

Cabling Planning

Conventional rack-type servers usually have their own storage, less independent configuration of separate storage network, routing to the main upstream LAN network, wiring planning can be 4-8 units per column to configure a network column header, and high-performance servers and rack-type servers, such servers are mainly responsible for high-speed data calculation, Typically with separate storage devices, high-performance servers and stand-alone storage devices are typically configured at a ratio of 2:1, with high performance servers and San switches, and storage devices that form multiple, multiple-point fiber high-speed transmission channels, as shown in Figure 1. From the network connection in Figure 1, it can be seen that any server, due to a sudden failure or panic, does not affect the normal transmission of data and extranet in the storage device, and any other server can process the data of the storage equipment in time through the San Exchange equipment to ensure the reliability of the core data transmission application.

Cabling for high-performance servers consists of two parts, one on LAN networks and the other on SAN storage networks. In the actual wiring scheme implementation process, the author has noticed that some of the consultants in the planning layout of the San region of high-performance servers, storage devices and San switching devices, with a rack-like server for each column to configure a 4-8-unit network header, this way, I do not recommend, Because of this, the wiring of the San switching device that is placed separately in each column header becomes complex, and a large number of interconnect fibers need to be configured between the two columns in order to achieve the multiple point-to-point connections between the network column headers of each of the San switching devices. Also, if you set up a network column header for a high-performance server for each column, also not conducive to the wiring of the San network, High-performance Server part of the fiber uplink LAN, part of the downlink San network, if the downlink of the San part of the fiber needs to go through the Network column header, in addition to waste wiring, but also caused by the number of hops too many, Lead to the overall channel between the fiber loss too much, the current data center room building in the San transmission channel is the vast majority of configuration Wanchaodo mode cable, such as Wanchaodo mode OM3 fiber support million trillion 300 meters under the distance to control attenuation under 2.6dB, if due to the overall planning of the cause of network wiring jump Too much to cause the overall channel excessive attenuation, because the planning unreasonable cause excessive attenuation will be very regrettable, even in a pre-connected scenario, it is possible to cause the attenuation to be too high, computed, the San area cabling method for each column header, and the total channel connector of the SAN network may reach 9 or more connection points. In view of the above analysis, for the San area cabling network, the author also recommended that centralized wiring management, wiring area to place San Exchange equipment, and the server from the pre-connected cable directly to the wiring area, rather than the traditional way of the column, this approach is usually the connection point of each channel can be controlled in 5 Connection points, but also more conducive to the implementation of the region's wiring management, saving the user's wiring investment, centralized SAN wiring management as shown in Figure 2. Because the SAN network wiring is relatively independent, it is not always important to place the wiring area of the SAN network with the MDA region of the LAN, the advantage of this is that in addition to reducing the average length of the optical cable in the area, reducing the wiring investment, more importantly, can reduce the LAN MDA wiring and line resonators by the pressure, make wiring clearer, Easier to manage and maintain and future expansion.

Figure 2

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