FAQ about Routing of Data Center


? Q: On the construction of network cables across long distances, when the unit encounters such situation, the office building is too wide, while the internet access point is on the left side of the building, so that internet access is available on each floor. To speed, how to solve?

A: Balanced twisted pair support for data applications is 100 meters, which is defined by international standards. Transmission of network signals over a distance of more than 100 meters will result in a number of uncertainties, depending on the performance margin of the cabling system, the performance margin of the network equipment, the construction conditions at the site, etc., and a quantitative indicator can not be obtained Guarantee. According to the case you mentioned, it is standard practice to set up two telecom rooms on one floor. The horizontal cable is divided into corresponding telecom rooms to ensure that the length of the horizontal link (from the patch panel to the information outlet) is not long Over 90 meters.

Of course, users can also make direct point-to-point connections (more than 100 meters) with high-performance, good-quality cables and modules, but the support of this line for network applications is not guaranteed, which means it may support xDSL or 10BASE-T signals, but may not be able to support higher rates.

Wiring design standards is to be followed, if too long, consider adding a relay in the middle, such as using a switch or hub to connect two sections of network cable. Do not take risks long, this will make the network communication brings uncertainty.

? Q: Our company has a network port is separated from the floor switch, after testing the switch, network port, and from the floor switch in the separation of the line, the computer has no problem, but the problem can only send packets can not be received Package, for a few computers are of no avail. Will you connect the main switch to the floor between the switches in the threading damaged?

A: It may seem that the line problem, provided that the switch port and this computer port in other lines to send and receive data packets. It is recommended that you use a wiring tester to perform channel transmission performance tests on this circuit, including jumpers on both ends, connectors at both ends (patch panel and information outlet), and laid cables. The test standard is based on the actual situation of choosing Class 5E or 6 class. Also confirm that the jumpers used meet the T568A / B line sequence standard.

? Q: What are the special requirements for Fiber Channel cabling in the data center computer room?

A: The cable channel in the data center computer room is mainly used for 10G network. When using, note the following points:

1, transmission distance: OM3 multimode fiber is 300m-550m, single-mode fiber is 10-40km

2, the use of fiber optic connectors and adapters for the SC, LC or network equipment in accordance with the type of port selection

If you use an open cable tray laying cable to reach the appropriate level of fire (A or B engine room)

The location of the optical wiring module (such as the top of the equipment cabinet, the open bridge, cabling cabinets and various cabinets)

? Q: Our company has a total of 3 floors of buildings, each with a computer ranging from 80-100 units, each layer of the computer distribution area of 300 square meters. Like this case, what should I do to make the wiring easier and more efficient? The current vague plan is to place a layer 3 switch in the center of each layer, and then connect the 3 switches through the PC server to achieve network sharing, and then through the router to achieve Internet access. I do not know if I can not do this?

A: From the exchange network architecture should be based on the 3-layer switchboard set up a convergence switch, aggregation switch access server as a network data sharing platform for users, and then converged switches through the appropriate router access Internet. point:

1, wiring network architecture and computer network architecture to adapt;

2, the floor wiring between the setting Note that the horizontal cable does not exceed 90m length;

3, the level of cabling system in line with the Ethernet switch transmission bandwidth, the proposed level of ultra-Category 5 or Category 6 cabling system, the backbone of multi-mode optical fiber (OM3), and configure the appropriate wiring module;

4, Should design a more detailed cabling system architecture diagram, and interoperability with network facilities clearly expressed.

? Q: After the network cabling is done, how to check it? Need to consider from what aspects?

A: The specific method of acceptance please refer to GB50312-2007 "Cabling System Project Acceptance Code", acceptance note the following points:

1, all information points 100% of the permanent link test, connection model according to the specification requirements;

2, The test index items are determined according to the network supported by the cabling system (such as Fast, Gigabit, Gigabit, Ethernet)

3, determine the function and accuracy of test instruments;

4, the test results should play a document to save;

5, to judge the quality of the project to make the standard (pass or fail).

6, the specification has a more detailed description, if there are still problems, can be raised.

? Q: We are in accordance with the a or b line standard to do. But look at the information that gigabit network cable has its own line, the problem came out. According to a or b standard line can run Gigabit? Gigabit is the use of eight lines to work together. If it is Gigabit half-duplex, is it right? Just need to use 4 lines? POE power supply is the use of four lines in the network cable to transmit electricity, then one hundred trillion line to say, but gigabit is using eight lines to transmit signals, is not gigabit port mode can not be achieved POE power it ?

A: Under normal circumstances, according to the wiring diagram of B card access network cable, but a project in the way of using the same card line, not A, B mix. The standard for wire bonding mainly depends on the type of network equipment port. Generally, 10M, 100M and 1000M networks are connected according to the standard connection mode. When the 10G network uses shielded wiring, there will be a special connection mode, which is specially combined with the installation manual provided by the manufacturer , For construction; Gigabit network is basically four pairs of lines all used, but also two-way work. POE power supply in two ways: one is the transmission of information on two pairs of lines, two pairs of power supply; the other way is to transmit information on the line that power transmission. POE power supply mainly depends on the function of network equipment, transmission line is no problem.

Gigabit Ethernet complies with the IEEE802.3ab standard to support the enhancement of more than five cabling systems, if your cabling system components and the entire channel are in line with Cat.5e standards, whether in accordance with a standard or b standard can support Gigabit . Gigabit Ethernet is full-duplex operation in 4 pairs of online, half-duplex Gigabit network equipment is not currently seen on the market.

PoE is divided into endpoint and mid-span two modes, endpoint is powered by the switch port, end-span is in the middle of the line load power, and now both modes support the load on the data line signal power, the two modes on the market Gigahertz products have.

There are two Gigabit interfaces: 1000BASE-T and 1000BASE-TX. They all use four pairs of wires, but in different ways.

1000BASE-TX, two pairs of 500M send, the other two pairs of 500M receiver, so you can reach 1000M full-duplex (2000M throughput). This interface, you must six types of cables to support.

1000BASET-T, is four pairs of the same send and receive 250M, can also be done 250 * 4,1000 M full-duplex transmission. This type of interface is available in Cat5e and Cat6e cables.

Now most devices interface 1000BASE-T.1000BASE-T device interface costs slightly higher than 1000BASE-TX, because 1000BASE-T requires equipment interface crosstalk cancellation technology.

? Q: In the access network this piece, CATV development prospects how? There is no trend to replace ADSL?

A: CATV generally uses HFC fiber optic copper hybrid access technology, which can support the transmission of cable television signals, voice, data and other information. It can also realize the integration of business networks, but from the current national industry regulations related policies and regulations: CATV network mainly uses cable television network. ADSL is also a copper access technology, it can also achieve multi-service access, but it is mainly used in voice and data services, is a broadband access for telecom operators. All access technologies such as the current adoption of EPON and so can achieve business integration, so technically able to achieve, all kinds of technologies have their own characteristics, can not fully say who can replace who.

? Q: I saw the term 'short link resonance' at one time of study. What is called 'short link resonance'?

A: This is a good question related to cabling design standards and product optimization.

The short link resonance you mentioned refers to a superposition of unbalanced or noisy signals in the link at short links (less than 15 meters), causing communication problems (shorter links between connectors Signal reflection easier to add). We all know that the permanent link is less than 90 meters, but the standard also requires more than 15 meters, so as to avoid the 'short link' problem. That is, link testing often fails when the link between two patch panels or modules is shorter than 15 meters. This phenomenon often occurs in Cat5e and Cat6e systems, and we are usually a 'short link' issue.

However, the problem is not so terrible, some manufacturers have done their own product optimization, or signal compensation technology, making the short link, but also to achieve the corresponding performance. For example, it can be used even at 7 meters or less. At the same time, tester vendors are also testing adapters to adapt to changes in cable products.

All we need to know is that links are not as short as possible.

? Q: Question 1: On the access network problems: access to the network a lot, but have not found a book can be fully understood. Can you sum it up? From dial-up to fiber access and all other access methods, to have a variety of access cases of the actual operation manual or program.

Question 2: green network. The network of different plots together to form a local area network. There are those ways? If I apply for a telecom SDH / DDN / MSTP green access, then in another place I use Netcom's SDH / DDN / MSTP can be connected to each other?

A: Question 1: LAN access to computer Internet is a variety of ways the current general users are mainly used the following:

1, Directly from the optical port (10M / 100M / 1000M) of the backbone Ethernet switch of local area network to the fiber distribution frame of telecommunication or other operators (such as technology, campus network, etc.) .

2, Adopt the export port of the backbone Ethernet exchanger and the router that accords with the correspondent network interface equipment of the corresponding communication business to carry on the intercommunication, mainly should consider the need of exporting the transmission bandwidth, generally adopt 2M (E1) based on the access way at present.

3, by the telecom operators to provide ADSL, EPON, wireless broadband access, etc., the same way to meet the export bandwidth as the main basis for operators to interface bandwidth requirements.

4, through the cable television network (HFC) user terminal equipment or set-top boxes into the Internet.

5, the most simple is through the telephone line plus modem dial-up.

6, of course, there are many kinds of access network technology. People's Posts and Telecommunications Publishing House has a special introduction to access network technology books, while the communications industry has released the access network system construction related specifications, these are from which you can understand the technical documents.

Question 2: If it is through the private line without switching network, under normal circumstances should use the same carrier's SDH / MSTP / DDN / equipment, but it is also possible that some telecom operators and some private network SDH interoperability for users Provide remote service. In specific projects can negotiate with the operator.

? Q: Now the entire network has been cloth line, testing all passed, but after a period of time, the connection on the PC shows that the network is disconnected, with the detector to detect all pass, how is this going?

A: The comprehensive wiring acceptance should use professional wiring test equipment, rather than using a simple on-off tester. Professional equipment in addition to on-off and line sequence, but also testing of insertion loss, crosstalk, return loss, delay and other electrical performance parameters to help you determine the wiring system installation is qualified.

Q: One of the problems facing the company now is that the early distribution of the line can not meet the current needs, coupled with the pattern of the office will be some time after time there is a big change, the walls are full of Line, chaos seven trick, although the leaders do not care about this area, but I always want to have a solution to this problem, I hope you will give me some valuable advice.

A: You can use the open office, that is, set the CP (rendezvous point) or multi-user information outlet wiring scheme in the "integrated wiring design specifications" GB50311-2007 has a clear provision, and in the description of the provisions of a specific explanation . If you still can not understand, you can ask further. However, there are several important points that you should be aware of:

1, set the location of network switches.

2, CP to FD horizontal cable transmission distance of less than 15 meters.

3, CP box size can be calculated according to the wiring module capacity, the current market is not stereotypes products

4, CP should not exist jumper connection.

? Q: May I ask in the process of integrated wiring, how to do a good job in the future expansion of rules and capital spending to do a good balance? In addition, the anti-rat pests damage to the line what good recipe?

A: The first question, this issue involves a broader, from the macro point of view, there are two points to consider, one is the choice of wiring products to be forward-looking, integrated wiring system as an infrastructure to support more than ten years or even twenty A few years of life cycle, reconstruction or re-construction, costly. The other is that in the wiring design, as far as possible the use of structured design, rather than direct connection point to point, make full use of patch panels or wiring module, making the cable becomes more flexible and flexible. (Based on mature products, do not need to worry about the increase of one or two sets of connection points, but also the performance impact).

The second question, some products have taken into account anti-animal bite problem. Especially in the fiber optic cable product development more mature (because the cable is the backbone, is very important, a wide range of impact), such as indoor armored cable, containing E-glass material rat anti-rat bites cable and so on.

In addition, if using open cabling, rodent control can be effectively avoided, because mice like the dark environment, not the open environment.

? Q: Before because the company in order to save costs, chose four cores as the network transmission, of which two cores as a telephone transmission common one network cable. However, the use of the latter part of the process of feeling LAN sharing reaction is very slow, can help me explain it?

A: This one question is actually an old one. The main reason for this phenomenon is that when a telephone line pair is in a ringing state when there is a data pair and a voice line pair in a pair of four pairs of cables, Crosstalk on the impact of the normal transmission of data packets