Design of a local information network. Coursework: Designing a local computer network Creating a local one. Restoration work of LAN maintenance
Course work
Designing a LAN in a secondary school
Introduction 3
- Creating a LAN at school 4
- Design part 8
2.1 Selection and justification of LAN construction technology 8
2.2 Data transmission medium analysis 8
2.3 Network topology 8
2.4 Access method 9
- Selection and justification of network hardware 10
3.1 Communication devices 10
3.2 Network equipment 13
3.3 Room layout 16
3.4 Calculation of cable quantity 19
- Network installation instructions 22
- Equipment cost calculation 30
Conclusion 31
References 33
Introduction
A local area network is a joint connection of several computers to a common data transmission channel, which ensures the sharing of resources such as databases, equipment, and programs. Using a local network, remote workstations are combined into a single system, which has the following advantages:
- Resource sharing - allows resources to be shared, e.g. peripherals(printers, scanners), all stations included in the network.
- Data sharing - allows you to share information located on the hard drives of workstations and servers.
- Software sharing - ensures the sharing of programs installed on workstations and the server.
- Processor resource sharing is the ability to use computing power to process data by other systems on the network.
Local development computer network will be held in the building of a comprehensive school.
The purpose of this work is to calculate the technical characteristics of the network being developed, determine the hardware and software, the location of network nodes, communication channels, and calculate the cost of implementing the network.
- Creating a LAN at school
In recent years, there has been a radical change in the role and place of personal computers and information technologies in the life of society. The modern period of development of society is defined as the stage of informatization. Informatization of society involves the comprehensive and massive introduction of methods and means of collecting, analyzing, processing, transmitting, and archival storage of large volumes of information based on computer equipment, as well as a variety of data transmission devices, including telecommunication networks.
The concept of modernization of education, the project “Informatization of the education system” and, finally, technological progress pose the task of forming an ICT - a competent person capable of applying knowledge and skills in practical life for successful socialization in the modern world.
The process of school informatization involves solving the following tasks:
- development of pedagogical technologies for the use of information and communication means at all levels of education;
- use of the Internet for educational purposes;
- creation and use of automation tools for psychological and pedagogical testing, diagnostic methods for monitoring and assessing the level of knowledge of students, their advancement in learning, establishing the level of intellectual potential of the student;
- automation of the school administrative apparatus;
- training in the field of communication and information technologies.
A local network unites computers installed in one room (for example, a school computer lab consisting of 8-12 computers) or in one building (for example, in a school building several dozen computers installed in different subject rooms can be combined into a local network).
Local Area Network (LAN) is a computer network covering a relatively small area.
In small local networks, all computers usually have equal rights, i.e., users independently decide which resources of their computer (disks, directories, files) to make publicly available over the network. Such networks are called peer-to-peer.
To increase the performance of the local network, as well as to ensure greater reliability when storing information on the network, some computers are specially allocated for storing files or application programs. Such computers are called servers, and a local area network is called a server-based network.
A typical school LAN looks like this. There is one Internet access point to which the corresponding router (ADSL or Ethernet) is connected. The router is connected to a switch (switch), to which user PCs are already connected. A DHCP server is almost always activated on the router, which means automatic distribution of IP addresses to all user PCs. Actually, this solution has both its pros and cons. On the one hand, the presence of a DHCP server simplifies the process of creating a network, since there is no need to manually network settings on users' computers. On the other hand, in the absence of system administrator a quite typical situation is when no one knows the access password to the router, and standard password changed. It would seem, why do you need to “get into” the router if everything works anyway? That's how it is, but there are unpleasant exceptions. For example, the number of computers at the school increased (another computer science class was equipped) and problems began with IP address conflicts on the network. The fact is that it is not known what range of IP addresses is reserved on the router for distribution by the DHCP server, and it may well turn out that these same IP addresses are simply not enough. If such a problem occurs, then the only way to solve it without going into the settings of the router itself is to manually register all network settings (IP address, subnet mask and gateway IP address) on each PC. Moreover, in order to avoid IP address conflicts, this must be done on each PC. Otherwise, manually assigned IP addresses may fall out of the range reserved for distribution by the DHCP server, which will eventually lead to an IP address conflict.
Another problem is that all computers connected to the switch and, accordingly, having access to the Internet through the router form one peer-to-peer local network, or simply working group. This working group includes not only the computers installed in the school computer lab, but also all other computers available at the school. This includes the director’s computer, the head teacher’s computer, secretaries’ computers, accounting computers (if there is one at the school), and all other computers with Internet access. Of course, it would be wise to divide all these computers into groups and assign appropriate rights to each user group. But, as we have already noted, no domain controller is provided, and therefore it will simply not be possible to implement this. Of course, this problem could be partially solved at the hardware level by organizing several virtual local networks(VLAN) and thereby physically separating student PCs from other computers. However, this requires a managed switch (or at least a Smart switch), the presence of which is very rare in schools. But even if there is such a switch, you still need to be able to configure virtual networks. You can even not use virtual networks, but install an additional router and switch and use different IP addressing (IP addresses from different subnets) for computers in the computer science class and all other computers. But again, this requires additional costs for purchasing the appropriate equipment and experience in setting up routers. Unfortunately, it is impossible to solve the problem of dividing school computers into groups isolated from each other without additional financial costs (the presence of a managed switch in a school is an exception to the rule). At the same time, such a division is not mandatory. If we consider the need for such separation from the point of view of network security, then the problem of protecting the computers of teachers and administration from attacks by students can be solved in another way.
- Design part
2.1 Selection and justification of LAN construction technology.
The main purpose of the designed computer network is to ensure communication between network computers and provide the ability to transfer files at speeds of up to 100 Mbit/s. Thus, Fast Ethernet technology will be used to build a LAN for all departments of the building.
LAN construction technologies. In this work, Fast Ethernet technology will be used to build a network, providing a data transfer rate of 100 Mbit/s. A star topology will also be used using unshielded twisted pair CAT5 cable as communication lines.
2.2 Analysis of the data transmission medium.
For data transmission in Fast Ethernet the 100 Base-TX standard will be used. A 4-pair CAT5 cable is used. All pairs participate in data transmission. Options:
data transfer rate: 100 Mbit/s;
type of cable used: unshielded twisted pair CAT5 categories;
maximum segment length: 100 m.
2.3 Network topology.
The topology of a network is determined by the placement of nodes in the network and the connections between them. The term network topology refers to the path along which data travels on a network. For Fast Ethernet technology, a star topology will be used.
To build a network with a star architecture, it is necessary to place a hub (switch) in the center of the network. Its main function is to ensure communication between computers on the network. That is, all computers, including the file server, do not communicate directly with each other, but are connected to a hub. This structure is more reliable, since if one of the workstations fails, all the others remain operational. The star topology is the fastest of all computer network topologies because data transfer between workstations passes through a central node (if its performance is good) over separate lines used only by these workstations. The frequency of requests for information transfer from one station to another is low compared to that achieved in other topologies.
2.4 Access method.
Fast Ethernet networks use the CSMA/CD access method. The basic concept of this method is as follows:
All stations listen to transmissions on the channel, determining the state of the channel;
Carrier check;
The start of transmission is possible only after the free state of the channel is detected;
The station monitors its transmission, when a collision is detected, the transmission stops and the station generates a collision signal;
The transmission is resumed after a random period of time, the duration of which is determined by a special algorithm, if the channel is free at that moment;
Several unsuccessful transmission attempts are interpreted by the station as a network failure.
Even in the case of CSMA/CD, a collision situation may arise when two or more stations simultaneously determine free channel and begin attempting to transfer data.
- Selection and justification of network hardware
3.1 Communication devices
Selecting a network adapter.
A network adapter is a computer peripheral device that
directly interacting with the data transmission medium, which
directly or through other communications equipment connects it with
other computers. This device solves the problem of reliable exchange
binary data, represented by corresponding electromagnetic signals, over external communication lines. The network adapter is connected via PCI buses to the motherboard.
A network adapter typically performs the following functions:
- registration of transmitted information in the form of a frame of a certain format.
- gaining access to the data transmission medium.
- encoding a sequence of frame bits with a sequence of electrical signals when transmitting data and decoding when receiving them.
- converting information from parallel to serial form and vice versa.
- synchronization of bits, bytes and frames.
TrendNet TE 100-PCIWN network cards are selected as network adapters.
Selecting a hub (switch).
A hub (repeater) is the central part of a computer network in the case of a star topology.
The main function of a hub is to repeat signals arriving at its port. The repeater improves the electrical characteristics of the signals and their synchronization, and due to this it becomes possible to increase the total cable length between the most remote nodes in the network.
A multiport repeater is often called a hub or hub, reflecting the fact that this device implements not only the signal repetition function, but also concentrates the functions of connecting computers into a network in one central device.
The lengths of cable connecting two computers or any two other network devices are called physical segments, so hubs and repeaters, which are used to add new physical segments, are a means of physically structuring the network.
A hub is a device whose total input channel capacity is higher bandwidth output channel. Since the input data streams in the concentrator are larger than the output stream, its main task is data concentration.
The hub is active equipment. The hub serves as the center (bus) of a star-shaped network configuration and provides connection to network devices. The hub must have a separate port for each node (PCs, printers, access servers, phones, etc.).
Switches.
Switches control network traffic and control its movement by analyzing the destination addresses of each packet. The switch knows which devices are connected to its ports and routes packets only to the necessary ports. This makes it possible to simultaneously work with several ports, thereby expanding the bandwidth.
Thus, switching reduces the amount of unnecessary traffic that occurs when the same information is transmitted to all ports,
Switches and hubs are often used on the same network; hubs expand the network by increasing the number of ports, and switches break the network into smaller, less congested segments. However, the use of a switch is justified only in large networks, since its cost is an order of magnitude higher than the cost of a hub.
The switch should be used in the case of building networks in which the number of workstations is more than 50, which includes our case, as a result of which we choose D-Link DES-1024D/E, 24-port Switch 10/100Mbps switches.
3.2 Network equipment
Selecting the cable type.
Today the vast majority computer networks uses wires or cables as a transmission medium. Exist Various types cables that meet the needs of all kinds of networks from large to small.
Most networks use only three main groups of cables:
- coaxial cable;
- twisted pair:
* unshielded (unshielded); o * shielded;
Fiber optic cable, single mode, multimode (fiber
optical).
Today, the most common type of cable and the most suitable in terms of its characteristics is twisted pair. Let's look at it in more detail.
Twisted pair is a cable in which an insulated pair of conductors is twisted with a small number of turns per unit length. Twisting the wires reduces electrical interference from outside as signals propagate along the cable, and shielded twisted pairs further increase the degree of noise immunity of signals.
Twisted pair cable is used in many network technologies, including Ethernet, ARCNet, and IBM Token Ring.
Twisted pair cables are divided into: unshielded (UTP -Unshielded Twisted Pair) and shielded copper cables. The latter are divided into two varieties: with shielding of each pair and shared screen(STP - Shielded Twisted Pair) and with only one shared screen (FTP - Foiled Twisted Pair). The presence or absence of a shield on a cable does not at all mean the presence or absence of protection of the transmitted data, but only speaks of different approaches to suppressing interference. The absence of a shield makes unshielded cables more flexible and resistant to kinks. In addition, they do not require an expensive ground loop for normal operation, like shielded ones. Unshielded cables are ideal for laying indoors inside offices, while shielded cables are best used for installation in places with special operating conditions, for example, near very strong sources of electromagnetic radiation, which are usually not found in offices.
Due to the selected Fast Ethernet 100Base-T technology and star topology, it is suggested that you select Category 5 unshielded twisted pair (UTP) cable.
Selection of connectors.
To connect workstations and the switch, RJ-45 connectors, 8-pin sockets, the cable of which is crimped in a special way, are selected.
When a computer is used to exchange information over the telephone
network, you need a device that can receive a signal from a telephone
network and convert it to digital information. This device
called a modem (modulator-demodulator). The purpose of the modem is to replace the signal coming from the computer (a combination of zeros and ones), electrical signal with a frequency corresponding to the operating range of the telephone line.
Modems can be internal or external. Internal modems are made in the form of an expansion card, inserted into a special expansion slot on motherboard computer. External modem, in contrast to the internal one, is made in the form separate device, i.e. in a separate case and with its own power supply, when the internal modem receives electricity from the computer's power supply.
Internal modem Advantages
- All internal models, without exception (unlike external ones), have a built-in FIFO. (First Input First Output - first to come, first to be accepted). FIFO is a chip that provides data buffering. Regular modem Every time a byte of data passes through the port, it requests an interrupt from the computer. The computer, using special IRQ lines, interrupts the operation of the modem for a while, and then resumes it again. This slows down the computer overall. FIFO allows you to use interrupts several times less often. This is of great importance when working in multitasking environments. Such as Windows95, OS/2, Windows NT, UNIX and others.
- When using an internal modem, the number of wires stretched in the most unexpected places is reduced. Also, the internal modem does not take up space on the desktop.
- Internal modems are a serial port on the computer and do not occupy existing computer ports.
- Internal modem models are always cheaper than external ones.
Flaws - They occupy an expansion slot on the computer motherboard. This is very inconvenient on multimedia machines that have a large number of additional boards, as well as on computers that work as servers in networks.
- There are no indicator lights that, if you have a certain skill, allow you to monitor the processes occurring in the modem.
- If the modem freezes, you can restore functionality only by pressing the “RESET” key to restart the computer.
External modems Advantages
- They do not occupy an expansion slot, and if necessary, they can be easily disabled and transferred to another computer.
- There are indicators on the front panel that help you understand what operation the modem is currently performing.
- If the modem freezes, you do not need to restart the computer; just turn off and turn on the modem's power.
Flaws
- A multicard with built-in FIFO is required. Without a FIFO, the modem will of course work, but the data transfer speed will drop.
- The external modem takes up space on the desktop and requires additional wires to connect. This also creates some inconvenience.
- It occupies the computer's serial port.
- An external modem is always more expensive than a similar internal one, because includes a housing with indicator lights and a power supply.
For our network we will choose internal ZyXEL modem Omni 56K. V.90 (PCTel) int PCI.
3.3 Room layout
All diagrams contain symbols:
SV - server.
PC - workstation.
K - switch.
Rice. 1 Network diagram on the first floor
Rice. 2 Network diagram on the second floor
Rice. 3 Network diagram on the 3rd floor
3.4 Calculation of cable quantity
Calculation of the total cable length by floor, required to build a local network, is given in tables 1,2,3. The cable is laid along the walls in special boxes.
Table 1. Cable length on the 1st floor.
K1-K2 16 meters
K1-K3 14 meters
The total cable length on the ground floor is 96 meters.
Table 2. Cable length on 2nd floor
|
Work station |
Length of cable From RS to K |
Cable length between switches:
K4K5 17 meters
The length of the cable from the server to K 4 is 1 meter
The total cable length on the second floor is 156 meters.
Table 3. Cable length on the 3rd floor
|
Work station |
Cable length from RS to K |
Cable length between switches:
K7K6 17 meters
K7K8 15 meters
The total cable length in segment C is 230 meters.
Cable length between floors is 2 meters
The total cable length of the entire local network, taking into account the safety factor, is (96+156+230+2+2)* 1.2=583.2 m.
- Network installation instructions
At the beginning of the development of local networks, coaxial cable was the most common transmission medium. It was and is used primarily in Ethernet networks and partly ARCnet. There are “thick” and “thin” cables.
Thick Ethernet is typically used as follows. It is laid along the perimeter of a room or building, and 50-ohm terminators are installed at its ends. Due to its thickness and rigidity, the cable cannot connect directly to the network card. Therefore, “vampires” are installed on the cable in the right places - special devices that pierce the cable sheath and connect to its braid and central core. “Vampire” sits so firmly on the cable that once installed it cannot be removed without a special tool. A transceiver, in turn, is connected to the “vampire” - a device that matches the network card and cable. And finally, a flexible cable with 15-pin connectors on both ends is connected to the transceiver - the other end is connected to the AUI (attachment unit interface) connector on the network card.
All these difficulties were justified by only one thing - the permissible maximum length of a “thick” coaxial cable is 500 meters. Accordingly, one such cable can serve a much larger area than a “thin” cable, the maximum permissible length of which, as is known, is 185 meters. With some imagination, you can imagine that a “thick” coaxial cable is an Ethernet hub distributed in space, but completely passive and does not require power. It has no other advantages, but there are more than enough disadvantages - first of all high price cable itself (about $2.5 per meter), the need to use special devices for installation ($25-30 per piece), inconvenient installation, etc. This gradually led to the fact that "thick Ethernet" slowly but surely disappeared from the scene, and is currently used in few places.
"Thin Ethernet" is much more widespread than its "thick" counterpart. Its principle of use is the same, but due to the flexibility of the cable it can be connected directly to the network card. To connect the cable, BNC (bayonet nut connector) connectors are used, installed on the cable itself, and T-connectors, which are used to route the signal from the cable to the network card. BNC type connectors can be crimped or dismountable (an example of a collapsible connector is the domestic connector SR-50-74F).
T-connector
To install the connector on the cable, you will need either a special crimping tool or a soldering iron and pliers.
The cable must be prepared as follows:
- Carefully cut so that its end is even. Place the metal sleeve (a piece of tubing) that comes with the BNC connector onto the cable.
- Remove the outer plastic sheath from the cable to a length of approximately 20 mm. Be careful not to damage any of the braided conductors if possible.
- Carefully unravel the braid and spread it apart. Strip the insulation from the center conductor to a length of approximately 5 mm.
- Install the center conductor into the pin that also comes with the BNC connector. Using a special tool, securely crimp the pin, fixing the conductor in it, or solder the conductor into the pin. When soldering, be especially careful and attentive - poor soldering will cause network failures after a while, and it will be quite difficult to localize this place.
- Insert the center conductor with the pin installed on it into the connector body until it clicks. A click means that the pin has settled into place in the connector and is locked there.
- Distribute the braided conductors evenly over the surface of the connector, if necessary, cut them to the required length. Slide the metal sleeve over the connector.
- Using a special tool (or pliers), carefully crimp the coupling until the braid is in reliable contact with the connector. Do not crimp too hard - you may damage the connector or pinch the insulation of the center conductor. The latter can lead to unstable operation of the entire network. But you also can’t squeeze too loosely - bad contact braided cable with connector will also lead to operational failures.
I note that the domestic CP-50 connector is mounted in approximately the same way, with the exception that the braiding in it is embedded in a special split sleeve and secured with a nut. In some cases this may be even more convenient.
Twisted pair cables
Twisted pair (UTP/STP, unshielded/shielded twisted pair) is currently the most common signal transmission medium in local networks. UTP/STP cables are used in Ethernet, Token Ring and ARCnet networks. They vary by category (based on bandwidth) and conductor type (flexible or solid). A Category 5 cable usually contains eight conductors twisted in pairs (that is, four pairs).
UTP cable
A structured cabling system built on Category 5 twisted pair cable is very flexible in use. Her idea is as follows.
For each workplace At least two (three recommended) four-pair RJ-45 sockets are installed. Each of them is connected with a separate category 5 cable to a cross-connect or patch panel installed in a special room - the server room. Cables from all workplaces are brought into this room, as well as city telephone inputs, dedicated lines for connecting to global networks, etc. Naturally, servers are installed in the premises, as well as office PBX, alarm systems and other communication equipment.
Due to the fact that the cables from all workstations are brought together on a common panel, any socket can be used to connect a workstation to a LAN, for telephony, or anything else at all. Let's say two sockets at the workplace were connected to a computer and a printer, and the third was connected to a telephone exchange. During the work process, it became necessary to remove the printer from the workplace and install a second phone in its place. There is nothing simpler - the patch cord of the corresponding outlet is disconnected from the hub and switched to the telephone cross-connect, which will take no more than a few minutes from the network administrator.
2-port socket
A patch panel, or interconnect panel, is a group of RJ-45 outlets mounted on a 19-inch wide plate. This is the standard size for universal communication cabinets - racks, in which equipment (hubs, servers, sources) is installed uninterruptible power supply and so on.). On the back side of the panel there are connectors into which the cables are mounted.
The cross, unlike the patch panel, does not have sockets. Instead, it carries special connecting modules. In this case, its advantage over the patch panel is that when used in telephony, the inputs can be connected to each other not with special patch cords, but with ordinary wires. In addition, the cross can be mounted directly on the wall - it does not require a communication cabinet. In fact, there is no point in purchasing an expensive communications cabinet if your entire network consists of one or two dozen computers and a server.
Cables with multicore flexible conductors are used as patch cords, that is, connecting cables between a socket and a network card, or between sockets on a connection panel or cross-connect. Cables with single-core conductors - for laying the cable system itself. The installation of connectors and sockets on these cables is completely identical, but usually cables with single-core conductors are mounted on sockets of user workstations, connection panels and cross-connects, and connectors are installed on flexible connecting cables.
Patch panel
Typically, the following types of connectors are used:
- S110 - the general name of connectors for connecting a cable to a universal cross-connect "110" or switching between inputs on a cross-connect;
- RJ-11 and RJ-12 are six-pin connectors. The former are usually used in general-purpose telephony - you can find such a connector on the cords of imported telephone sets. The second is usually used in telephone sets designed to work with office mini-PBXs, as well as for connecting cables to ARCnet network cards;
- RJ-45 is an eight-pin connector usually used to connect cables to Ethernet network cards or for switching on the connection panel.
RJ-45 connector
Depending on what needs to be connected with what, different patch cords are used: “45-45” (on each side an RJ-45 connector), “110-45” (on one side S110, on the other - RJ-45 ) or "110-110".
To install RJ-11, RJ-12 and RJ-45 connectors, special crimping devices are used, which differ in the number of knives (6 or 8) and the size of the socket for fixing the connector. As an example, consider installing a Category 5 cable to an RJ-45 connector.
- Carefully trim the end of the cable. The end of the cable must be smooth.
- Using a special tool, remove the outer insulation from the cable to a length of approximately 30 mm and cut the thread embedded in the cable (the thread is designed to make it easier to remove longer insulation from the cable). Any damage (cuts) to the conductor insulation is absolutely unacceptable - that is why it is advisable to use a special tool whose cutter blade protrudes exactly to the thickness of the outer insulation.
- Carefully separate, unravel and align the conductors. Align them in one row, while observing the color coding. There are two most common color pairing standards: T568A (recommended by Siemon) and T568B (recommended by ATT and in fact the most commonly used).
On the RJ-45 connector, the colors of the conductors are arranged as follows:
The conductors must be located strictly in one row, without overlapping each other. Holding them with one hand, cut the conductors evenly with the other so that they protrude 8-10 mm above the outer winding.
- Hold the connector with the latch facing down and insert the cable into it. Each conductor must fall into its place in the connector and rest against the limiter. Before crimping the connector, make sure that you have not made a mistake in wiring the conductors. If the wiring is incorrect, in addition to the lack of correspondence with the contact numbers at the ends of the cable, which is easily detected using a simple tester, a more unpleasant thing is possible - the appearance of “splitted pairs”.
To identify this defect, a conventional tester is not enough, since electrical contact between the corresponding contacts at the ends of the cable is ensured and everything seems to be normal. But such a cable will never be able to provide normal connection quality even in a 10-megabit network over a distance of more than 40-50 meters. Therefore, you need to be careful and take your time, especially if you do not have enough experience.
- Insert the connector into the socket on the crimping device and crimp it to the stop stop on the device. As a result, the latch on the connector will snap into place, holding the cable stationary in the connector. The contact blades of the connector will each cut into its own conductor, ensuring reliable contact.
In the same way, you can install RJ-11 and RJ-12 connectors using the appropriate tool.
No special crimping tool is required to install the S110 connector. The connector itself is supplied unassembled. By the way, unlike “disposable” RJ-type connectors, the S110 connector allows for repeated disassembly and reassembly, which is very convenient. The installation sequence is as follows:
- Remove the outer insulation of the cable to a length of approximately 40 mm, spread the pairs of conductors apart without unraveling them.
- Secure the cable (in the half of the connector that does not have a contact group) with a plastic tie and cut off the resulting “tail”.
- Carefully place each wire into the organizer on the connector. Do not unravel the pair longer than required - this will degrade the performance of the entire cable connection. The pairing sequence is usual - blue-orange-green-brown; in this case, the light wire of each pair is laid first.
- Using a sharp tool (side cutters or a knife), trim each conductor along the edge of the connector.
- Replace the second half of the connector and crimp it with your hands until all the latches click into place. In this case, the knives of the contact group will cut into the conductors, ensuring contact.
Fiber optic cable
Fiber optic cables are the most promising and fastest-performing signal propagation medium for local networks and telephony. In local networks, fiber optic cables are used to operate over the ATM and FDDI protocols.
Connector stripper and crimper
Optical fiber, as its name suggests, transmits signals using pulses of light. Semiconductor lasers and LEDs are used as light sources. Optical fiber is divided into single-mode and multimode.
Single-mode fiber is very thin, its diameter is about 10 microns. Thanks to this, the light pulse passing through the fiber is less often reflected from its inner surface, which ensures less attenuation. Accordingly, single-mode fiber provides longer range without the use of repeaters. The theoretical throughput of single-mode fiber is 10 Gbps. Its main disadvantages are high cost and high complexity of installation. Single-mode fiber is mainly used in telephony.
Multimode fiber has a larger diameter - 50 or 62.5 microns. This type of optical fiber is most often used in computer networks. The higher attenuation in multimode fiber is due to the higher dispersion of light in it, due to which its throughput is significantly lower - theoretically it is 2.5 Gbps.
Special connectors are used to connect the optical cable to active equipment. The most common connectors are SC and ST types.
Installing connectors on a fiber optic cable is a very responsible operation that requires experience and special training, so you should not do this at home without being a specialist.
- Equipment cost calculation
The cost of components is shown in Table 4 (according to the M-video online store in Balakovo).
Table 4 equipment cost
The table shows that the costs of network design do not exceed reasonable limits.
- Prospects for network development
The LAN presented in this work can develop and expand. At this stage, the following measures can be taken to improve the local network:
Connecting an additional network segment on the second and third floors;
Connecting additional workstations on any part of the network;
Installation of managed switches in the most loaded network segments (directly in computer classes);
Unloading the most loaded network segments by splitting it into branches;
Software updates to improve network quality.
Conclusion
During the work, a local area network was developed, consisting of 38 workstations and 1 server based on Fast Ethernet technology, the most common type of network at present, the advantages of which include ease of configuration and low cost of components. The star topology used in the project provides the possibility of centralized network management and makes it easy to find a failed node. The network is built taking into account future development. The server operating system is selected Windows Server 2003 R2. The required amount of network equipment is calculated, its price is given, data and calculations of the equipment used are provided, construction costs are 66,539 rubles. A detailed network plan has been drawn up, indicating all the characteristics of the components used. The design tasks were generally completed. The work has all the necessary data and calculations to build a network.
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- Guk M. Hardware of local networks. Encyclopedia - St. Petersburg: Peter, 2000. -576 p.
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- Dan Holme, Nelson Rest, Daniel Rest. Setting up Active Directory. Windows Server 2008. Microsoft training course / - M: Russian edition, 2011 - 960 p.
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their regulatory documents.
Procedure for designing local networks
Typical LAN design can be performed in several stages and involves determining the following characteristics:
· main and secondary tasks assigned to the network;
· functionality networks;
· the throughput of various sections and the nature of the information transmitted;
· type of network being installed;
· Possibility of laying cables indoors and ensuring their safe operation;
· LAN structure, its hierarchy and main parts by departments, workplaces;
· possibilities for further expansion of the network;
· the need to connect to existing local networks of the enterprise and to the global Internet;
· Possibility of using information security tools.
All work that involves the design of computer networks is carried out in strict accordance with the preliminary plan developed on the basis of the technical specifications. One of the priority conditions is ease of maintenance, installation, and, if necessary, dismantling of the enterprise local network.
Initial data
The importance of this stage is associated both with the need to streamline the requirements for the created drug and its individual components to ensure the possibility of making informed specific decisions in the future, and with its justification.
While creating new network For any enterprise, it is advisable to take into account the following factors:
· Required network size (currently, in the near future and forecast for the future).
· Structure, hierarchy and main parts of the network (by divisions of the enterprise, as well as by rooms, floors and buildings of the enterprise).
· The main directions and intensity of information flows on the network (currently, in the near future and in the long term). The nature of the information transmitted over the network (data, digitized speech, images), which directly affects the required transmission speed (up to several hundred Mbit/s for high-definition television images).
· Technical characteristics of equipment (computers, adapters, cables, repeaters, hubs, switches) and its cost.
· Possibility of laying a cable system in and between rooms, as well as measures to ensure cable integrity.
· Network maintenance and control reliability and safety.
· Requirements for software in terms of permissible network size, speed, flexibility, differentiation of access rights, cost, ability to control information exchange, etc.
· The need to connect to global or other local networks.
It is quite possible that after studying all the factors, it turns out that you can do without a network, thereby avoiding quite large costs for equipment and software, installation, operation, support and repair of the network, salaries for maintenance personnel, etc.
Network by compared to stand-alone computers, it gives rise to many additional problems: from the simplest mechanical ones (computers connected to a network are more difficult to move from place to place place) to complex information (the need to control shared resources, prevent viruses from infecting the network). In addition, network users are no longer as independent as users of stand-alone computers; they must adhere to certain rules, obey established requirements that must be taught to them.
Finally, net acutely raises the issue of information security and protection from unauthorized access, because from any computer on the network you can read data from shared network drives. Protect one computer or even several singles are much easier than a whole one net. Therefore, it is advisable to start installing a network only when without a network work becomes impossible, unproductive, when the lack of intercomputer communication hinders the development of business.
Requirements and solutions when choosing the size and network structures, network hardware and software will be discussed in subsequent sections. At the beginning of network design, it is necessary to carry out a complete inventory" existing computers and their software, as well as peripheral devices (printers, scanners, etc.). This will eliminate unnecessary duplication (equipment and software can now be shared resources), as well as set tasks for modernization (upgrade) of both hardware and software. To correctly determine the characteristics of computers, it is advisable to use special diagnostic programs or built-in OS programs (for example, in the OS Windows Millennium is program"System Information" from the Utilities section and program"System" from the control panel). You should choose program options that provide the correct data ("old" diagnostic programs may incorrectly indicate the processor type and OS version), and also data storage in a file (this is especially valuable when there are a large number of computers). In addition, you should pay attention to the presence of a built-in network card or network controller on the system board, as well as the type they support network standards(usually supported Ethernet network on twisted pair, but it is important to know its type - 10/100/1000 Mbit/s). Not all characteristics of computers that are important when combining them into net, can be determined in the ways described above. From the documentation accompanying the computer or after opening system unit it is possible and necessary to determine the number and type of free expansion slots (connectors), as well as the maximum power power supply. This is necessary to assess the possibility of installation in computer new boards.
Equipment selection
When choosing network equipment, many factors must be taken into account, in particular:
· level of equipment standardization and its compatibility with the most common software;
· speed of information transfer and the possibility of its further increase;
· possible network topologies and their combinations (bus, passive star, passive tree);
· exchange control method online ( CSMA/CD, full duplex or marker method);
· permitted types of network cable, its maximum length, immunity to interference;
· cost and specifications specific hardware (network adapters, transceivers, repeaters, hubs, switches).
All this is often neglected, but in vain: replace software It’s relatively simple, but replacing equipment, especially cable laying, is sometimes very expensive, and sometimes it’s simply impossible. First queue the applicability for the network case under consideration should be analyzed Ethernet, as the most popular, inexpensive and allowing development ( Fast Ethernet And Gigabit Ethernet).
The problem of choosing a cable type was discussed in some detail earlier. Assuming that the possibility of choice in this case exists, it is worth repeating the main arguments in favor of one or another choice (see Table 15.1).
| Table 15.1. Arguments when choosing a cable type | |||
| Cable type | Arguments for choosing | ||
| behind | against | ||
| unshielded twisted pair UTP(category 3 or higher) | · affordability; · availability of tools for installing connectors (RJ45); · ease of cable installation (flexible); · relative ease of repair in case of damage; · support for future high-speed networks (Fast and Gigabit Ethernet) when using cable category 5 or higher. | · relatively low immunity to electromagnetic interference; · relatively small permissible distances of cable connections, especially for high-speed networks; · impossibility of using connections in external areas (between buildings). | |
| shielded twisted pair STP (braided shield) 1 | · increased resistance to electromagnetic interference. | · slightly higher price compared to cable type UTP. | |
| shielded twisted pair FTP (foil shield) 2 | similar to the previous cable type | ||
| multimode fiber optic cable | · practical insensitivity to external electromagnetic interference and absence of self-radiation; · support for promising high-speed networks, including over distances that are inaccessible when using twisted pair cables. | · relatively high price of cable and network equipment; · complexity of installation (requires special tools and highly qualified personnel); · low maintainability; Sensitivity to environmental factors (may cause clouding fiber optics). | |
| single-mode fiber optic cable | · improved technical characteristics compared to multimode cable (possibility of increasing transmission speed or length of connections). | · higher price; · complex installation and repair. | |
| wireless connections (radio and infrared channels) | · eliminating the need to organize a cable system; · mobility of workstations (ease of moving them inside buildings or near central computer with radiating antenna); · possibility of organization global networks(using radio channels and satellite communications). | · relatively expensive equipment; · strong dependence of connection reliability on the presence of obstacles (for radio waves) and dust in the room (for infrared channels); · rather low transmission speed (up to a maximum of several Mbit/s) and the impossibility of significantly increasing it. |
Currently, for organizing local networks, in the vast majority of cases, unshielded twisted pair UTP. More expensive options based on shielded twisted pair, fiber optic cable or wireless connections are used in enterprises where there is a really urgent need for this. For example, optical fiber can be used for communication between remote network segments without loss of speed. Recommendations By organization of the cable system, including those contained in the standards for structured cabling systems ( SCS), are discussed in a separate section “Design of a cable system” in Lecture 16.
Another important task is the choice of computers. If for workstations or non-dedicated servers they usually use those computers that are already available in the enterprise, then dedicated server It is advisable to purchase specifically for the network. It is better if it is a fast-acting specialized computer-server, designed taking into account the specific needs of the network (such servers are produced by all largest producers computers).
Server requirements:
· The fastest possible processor (Microsoft recommends for its operating system Windows systems Server 2003 processor with a clock speed of at least 500 MHz). Typical value clock frequency The processor for the server is now 2-3 GHz. For large networks, multiprocessor servers (sometimes up to 32 processors) are also used.
· Large amount of RAM (Microsoft recommends a memory volume of at least 256 megabytes for its operating system Windows Server 2003, the same requirements from Novell for NetWare 6). The typical amount of server RAM is now 512 MB-20 GB. Large server memory is even more important than processor speed, as it allows for efficient use of caching disk information, storing in memory copies of those areas of the disk with which the most intensive exchange is carried out.
· Fast hard disks large volume. The typical server disk size is now 150-500 GB. Drives must be compatible with network operating system (that is, their drivers must be included in the set of drivers supplied with the OS). SCSI drives are widely used and are faster than traditional IDE drives. Servers often provide the ability to hot-swap disks (without turning off the server's power), which is very convenient.
· Specialized servers already contain network adapters with optimal characteristics. If a regular server is used Personal Computer, then the network adapter for it should be chosen the fastest.
· Video monitors, keyboards and mice are not required server accessories, since the server, as a rule, never operates in regular computer mode.
If it is possible to select computers for workstations, then it is worth analyzing the feasibility of using diskless workstations (with loading the operating system through net). This will immediately reduce price network as a whole or will allow you to buy better computers at the same cost: with fast processors, with good monitors, with large RAM. True, at present the use of diskless computers is considered not the most the best solution. Indeed, in this case, all the information computer gets through net and transmits to net, which can cause excessive network load. Diskless workstations are acceptable only for small networks (no more than 10-20 computers). Ideally, a significant portion of all information flows (at least 80%) should remain inside the computer, and network resources should be accessed only when truly necessary. Thus, the mentioned “80/20 rule” also applies in this case.
Upon refusal to use floppy disks on each computer on the network you can significantly increase it sustainability to viruses and unauthorized access to data. Drive floppy disk It may well be only on one workstation of a segment or even the entire network. And this work station must be controlled network administrator. It can be located in a separate room along with hubs, switches, and routers.
For any network, the situation of interruptions in the power supply system is extremely critical. Despite the fact that many network software take special measures against this, as well as against other hardware failures (for example, duplicate disks), the problem is very serious. Sometimes turning off the power can completely and permanently remove net out of service.
Ideally, all network servers (preferably workstations) should be protected from power failure. The easiest way to achieve this is if server There's only one on the network. In the event of a power failure, the uninterruptible power supply switches to powering the connected computer from the battery and sends a special signal to the computer, which in a short time completes all current operations and saves the data to disk. When choosing an uninterruptible power supply, you must first of all pay attention to the maximum power that it provides, and for the time it maintains the rated voltage level (this time ranges from several minutes to several hours). Price devices are quite high (up to several thousand dollars). Therefore, it is advisable to use one uninterruptible power supply for two or three servers.
Most fail-resistant power supply for portable computers (laptops). The built-in battery and low power consumption ensure their normal operation without external power supply for one to two hours or even more. If we also take into account the low level of radiation and high quality images of the monitors of these computers, then it is worth seriously considering the possibility of using laptops as workstations, and probably not too powerful, a non-dedicated server. Moreover, many laptops have built-in network adapters of fairly good quality. It is especially convenient to use laptops in peer-to-peer networks with many servers. The use of external uninterruptible power supplies in similar cases becomes too expensive a pleasure.
In addition to the problems listed above, the network designer has to solve problems related to the choice of network adapters, repeaters, hubs, switches and routers, but enough has already been said about this in previous chapters. It is only worth noting that performance network and its reliability determined by its lowest quality component. When buying expensive hubs or switches, you should not save on, for example, network adapters. The opposite is also true. It is desirable that all equipment components match each other as closely as possible.
Definition network model
The network model determines how data is stored and the location of the communication lines over which this data is transmitted. Each network can implement one or several standard models. Currently, four models are most common, providing users with access to network applications and data:
1. Distributed environment (mainframe environment)
This model was the very first and remains popular to this day. All network resources of this model are located on a server, which is responsible for managing and storing all company data. Each network user accesses the server from their video terminal or diskless workstation to run processes on the server.
The main advantages and disadvantages of this environment:
The server is the most vulnerable component to network failures
No need to upgrade client workstations to support new applications
Reduced network performance when the server is overloaded
Impossibility of further modernization and expansion in case of incorrect server selection
Easily manage security issues related to physical access to the server.
2. Client/server environment
At the current stage of technology development sharing data and resources, this model is the most popular and can be implemented in organizations of all sizes. Here the server is used only to provide access to applications and store generated data. All data processing is performed on the workstation, which improves network performance and reduces server load.
The main advantages and disadvantages of the client/server environment:
Need for more careful planning than other models
Ability to operate workstations even in the absence of a server
In case of network modernization, the need to increase the performance of not only the server, but also the workstation
Insufficient security of data stored on workstations
Expandable to industrial network level
3. Peer-to-peer environment
This model is designed for small (up to 15 workstations) local networks and is most often deployed in small offices. The principle of its operation is based on the fact that each workstation operates in server mode, providing access to its data and devices to any other station that has the necessary permissions for this.
Advantages and disadvantages of the peer-to-peer model:
Attractive cost/benefit ratio due to the lack of a dedicated server
Workstations are granted access to all resources
Lack of centralized management and security
Inability to convert to a large network
Possibility of failure of the entire network after the failure of an individual workstation
4. WWW-based environment
The structure of the model resembles a mainframe environment, in which a central server provides its “pages” of information for users to view and interact with. Each user of such a network can use these pages either on their local machine or on the server.
The main advantages and disadvantages of this environment:
Attractive cost/effectiveness ratio when used to combine local and global networks
The ability to install and update application versions without the need for direct interaction with client workstations
The most vulnerable network link to failures is the Web server.
Insufficient security due to external network access
Ability to deploy in low bandwidth or high schedule environments
Possibility of integration with the Internet.
Software selection
Network OS
After selecting the optimal network model and compiling lists of required applications, network professionals and users should identify possible network operating systems. The factors taken into account when making this decision are very similar to those discussed above:
Cost and licensing scheme
Easy installation and configuration
Ease of use
Minimum maintenance effort
Available level technical support
Computer resource requirements
Hardware support
Possibility of subsequent modernization
Level of support for independent developers (both application software and the OS itself)
Training opportunities for system administrators
Hardware Selection
The selected software6 determines the requirements for hardware. Network hardware requirements can be divided into three main types:
Server hardware requirements
Workstation hardware requirements
Requirements for peripheral devices (printers, modems, scanners, etc.)
It is recommended to install equipment from a company that is a leader in this market area, offers good support for its products, and provides solutions to compatibility issues between its hardware and hardware from other manufacturers.
The choice of server hardware is almost entirely determined by the network operating system used, and workstation hardware is determined by the applications that are planned to run on them. It is advisable to divide user equipment into several categories. For example, older PC models are recommended for software developers, CAD developers, artists, company analysts, for administrative assistants, sales agents, secretaries, etc. – standard PC models, for executives and managers - older PC models or, if they move frequently, then powerful portable PCs.
The last point to consider is peripherals. Typically, their choice is determined by the commercial requirements of each department. For example, is there a need for high-quality graphics printing? Is it required high speed print? Do I need a color printer to work?
It is advisable to locate peripheral devices in places where they will be accessible to the maximum number of users.
When preparing the final documentation for network hardware, the following basic specifications must be drawn up:
Desktop Hardware:
Manufacturer and model of the system (indicate separately for different categories of users)
CPU
Hard disks
Network adapters
Server hardware
System manufacturer and model
CPU
Hard drives (indicate all backup methods: mirroring, duplication, use of RAID arrays)
Network adapters
Additional peripherals
Peripheral System Manufacturer and Model
Node specific settings
Interfaces used (serial, parallel or other)
Network traffic assessment
After selecting the final hardware and software configuration of the network, it is necessary to evaluate the volumes and types of data transmitted in it in accordance with the data flow diagram. This will make it possible to determine possible periods of maximum and average network load, evaluate its scalability, and analyze the placement of information on servers and distributed information processing within work groups. This will make it possible to optimize the network architecture to evenly distribute the load, correctly segment it, and select the necessary network devices such as hubs, switches, routers and gateways.
Documentation
The network project documentation must contain the following information:
Commercial requirements
Logic circuit
Physical diagram
Application software (cost estimate)
Network software (cost estimate)
Hardware (servers, workstations and peripherals) (cost estimate)
Network Hardware (Cost Estimate)
General cost estimate
For each item, it is necessary to provide brief explanations about what alternatives existed and why a particular solution was chosen.
Administration
Concept " network administration" describes all aspects of installing and maintaining users/groups or files/directories. Although the meaning of this term is the same in all network environments, the operation network administrators differs significantly at different nodes.
The level of technical knowledge and operational skills of administrators also varies significantly. The following list contains questions that a network administrator should know the answers to:
How to register new users?
How to delete already registered users?
What is the volume structure on the server?
What directories are located in separate volumes?
How are reservation events planned?
Are there any special node configuration requirements?
What is the security level of each department or user directory?
Is it necessary to copy data to a central server in order to back it up in case of local equipment failure?
How is the server configured?
What causes possible server failures?
The following list describes all the main support responsibilities of network administrators normal operation server.
To organize management and support of the network, documentation is required that would contain the following main sections:
Working with users
User naming conventions
Rules for registering and deleting users
Information Management
Volume naming conventions
Directory structure (applications, user directories, department directories)
Directory size restrictions (optional)
Network management
Server naming conventions
About routers and gateways
Safety
Login scenarios/privileges for various departments
Restricting access using passwords
Determining access hours
Recovery Tools ( boot disks, bad sector editors, certain server configuration files, etc.).
Tracking (keeping statistics), resolving emerging problems
To maintain an operational state of the network, it is necessary to develop recovery plan after an emergency and a network support plan. A typical network recovery plan includes the following:
Determine the importance levels of all applications and systems (essential, vital, critical)
Drawing up descriptions of environmental systems (electrical, heating/cooling)
Identifying the teams responsible for troubleshooting and the situations in which these groups should be called upon
Determining the types of support groups provide
Determining hardware characteristics (this information is taken from the documentation)
Assessing and drawing up a contingency plan (downtime, replacement, offline operation)
Selecting the first person to notify about a network outage
Determining actions in non-standard situations (fire, bomb threat, natural disaster)
Scheduling outages and testing of critical systems
Despite the seeming triviality of these points, they are the main points not only for the correct functioning of the network, but also for a successful career as a network administrator.
The responsibilities of the network maintenance department also include user support , organizing events to train them and providing assistance in solving their problems. Support can be provided in the form of Email, a central database to which users turn with questions, in the simplest case - telephone communication.
Maintaining statistics and further analysis of failures of a certain type (some type of equipment constantly fails, there are certain factors that affect the stability of applications) will allow you to make the right decision about the need to upgrade or replace any component of the network environment.
Main stages of LAN design
Before carrying out work on installing a LAN, activities are carried out to develop and design local networks. Various specialists can be involved in this process, who must take into account all the design features of the building and individual premises where the LAN is planned to be installed. The result is a technical project drawn up
in accordance with the norms and rules adopted in the Russian Federation. It includes installation diagram
local network, description of its main characteristics, indicating regulatory
their regulatory documents.
Unix LLC offers clients LAN design services of any level of complexity. It is necessary to create a local computer network when an organization needs a common data transmission channel to which various office equipment. The development of such projects for small offices is not difficult, but the design of an enterprise LAN is large-scale engineering problem, requiring complex solutions. Specialists must create a large, reliable system, integrating a large number of computers and other equipment, software in order to ensure proper installation of the LAN.
The first stage in the design of LAN networks is the preparation of technical specifications. IN this document contains all the Client’s wishes regarding the number of workplaces, distribution points, and their placement. The features of the system itself are also taken into account - for example, its category. The basis is most often complex - access to computer and telephone networks needed by all employees. The absence of technical specifications will make it impossible to develop a project, and a correctly drawn up technical specification will allow you to get a high-quality project for the installation of computer networks.
Our company’s specialists provide the Client with the necessary consultations for the correct formation of requirements for technical specifications. If the office is small, a floor plan indicating the desired location of network elements will be sufficient from the Client. It is advisable to send information to the following points:
- number and location of sockets
- Suggestions on technical nuances of network operation
- proposed equipment and materials
Using the information received, the Design Department creates a sketch that identifies all cable routes. After this, an estimate is drawn up indicating the cost of equipment, materials and services.
Development of a LAN project for large organizations
Work on designing an enterprise LAN is more labor-intensive and has an integrated approach, taking into account all the features of the IT infrastructure. Technical documentation is being developed, which includes:
- Development of joint work of computers included in the network. The information interaction of devices is formed, the software used is taken into account.
- Preparation of a cable system project. According to the building plan, cable routes are determined, locations for switching equipment are determined, and specifications are drawn up according to it.
There are three main tasks that must be performed when designing an organization's LAN:
- development of the most efficient network configuration
- selection of passive and active network equipment
- ensuring data security
Passive LAN equipment
In most cases, LAN design does not automatically select one type of equipment; the Client is offered several options based on his wishes for cost and quality. To the complex passive devices includes computer sockets, cable channels, cabinets for installing telecommunications equipment, patch panels. The calculation of ports for organizing communication between nodes, the length of cables and cable channels is carried out, all nodes are indicated in the drawing.
Active equipment for LAN
When the network topology is formed and the location of all passive components is indicated, the design of the enterprise LAN proceeds to determining the type and number of active equipment to be connected:
- Switches. Necessary for uniting network nodes within a certain network segment or segments.
- Routers. They connect the local network and the Internet in accordance with established requirements, and filter traffic.
LAN laying provides guaranteed performance information resources and services with the required levels of availability, reliability, scalability, security and manageability. LAN (local area network) This is a set of software and hardware that includes many components and assemblies. The Customer's LAN network subsystem is designed to satisfy the needs of subscribers in providing information interaction and data exchange aimed at carrying out the Customer's business processes.
Most often, a LAN is organized using Ethernet and/or Wi-Fi technologies. For the construction and installation of a LAN, switches, routers, wireless access points (wi-fi), modems, optical (fiber-optic lines) and copper communication lines, etc. are used.
For remote connection A VPN connection is most often used to a LAN. VPN is a technology that allows you to organize one or more network connections over another network (internet).
Selection and justification of LAN construction technology
The choice of technology, architecture and equipment for LAN construction is determined by the following factors:To achieve the best results in terms of LAN performance, reliability, manageability, and scalability, a modular and hierarchical approach to data transmission system design is required. This approach allows you to expand the LAN optimally by adding new blocks without affecting the remaining components of the network structure, and provides an extremely high degree of certainty in the behavior of the LAN, which facilitates troubleshooting.
LAN provides its subscribers with the following information services:
The LAN consists of the following subsystems:
We work with the full range of fiber optic products (FOCL), copper pairs, server cabinets, patch panels, equipment wireless networks(wi-fi), sockets, etc. Our company has modern equipment and software for building (laying) LAN. Upon delivery of the LAN, a full report on testing of all installed communication lines is attached. LAN construction is carried out using active and passive network equipment from leading manufacturers such as Cisco, Hewlett-Packard, 3COM, etc. The GREEN EFFECT company carries out the construction and installation of LANs for office, industrial, public and residential buildings.
LAN design
The design department of the GRIN EFFECT company provides a full range of LAN (local area network) design services.At the first stage of LAN design, an inspection of the facility, negotiations with the customer, and identification of tasks and requirements for the LAN are carried out.
Based on the results of research and analysis of initial data, an optimal project for building a local computer network is developed, which includes all the wishes and requirements of the customer. The LAN project includes: detailed plans location of system elements; schematic and structural diagrams of connections, cable routing, cable log. A specification of equipment and materials, an estimate for the installation of a LAN and statements of work performed are also drawn up.
LAN design is carried out in accordance with Decree of the Government of the Russian Federation dated February 16, 2008 No. 87 “On the composition of sections of design documentation and requirements for their content”, regional building codes and technical specifications requirements.
When designing a LAN, the requirements of existing legislation and regulations on ecology, labor protection and fire safety are taken into account.
Pre-project survey
The purpose of the pre-project survey is to determine a set of measures and develop technical proposals taking into account the generated standard solutions. Based on the results of the survey, our design engineers will help the Customer develop a competent technical specification (TOR) for the design of a LAN.Technical specifications (TOR) LAN
Customer requirements form the basis technical specifications (TOR) LAN and are the primary document from which work on creating a local computer network begins. In addition to technical requirements, in the first stages of LAN design work, data obtained during the pre-design survey is used as initial information. Any design begins with a correctly written technical specification approved by the customer. The terms of design and the selection of the necessary equipment for the construction of a LAN, described in the technical specification, depend on a well-written technical specification.The composition of LAN design documentation is regulated by Government Decree Russian Federation“On the composition of sections of project documentation and requirements for their content” dated February 16, 2008, No. 87.
LAN design documentation (stage “P”)
A well-developed LAN concept and technical specifications provide the basis for creating a LAN outline plan - a single set of solutions designed to ensure a given LAN operation mode. The preliminary design determines the optimal LAN structure and cabling route, the location and composition of telecommunications infrastructure elements, an idea of the project budget, as well as a number of other parameters that will facilitate the selection of specific solutions.LAN design documentation consists of text and graphic materials that define space-planning, design and technical solutions for the construction or reconstruction (modernization) of a LAN.
The basis for the development of a LAN project is the architectural, construction, technological and engineering parts of the building design. The LAN project is focused on using the most efficient and well-proven equipment and component materials. Competent design means high speed of construction work and LAN maintenance. Error-free project calculation – minimizing equipment costs.
Working documentation of LAN (stage “P”)
At the next stage, working documentation for the LAN is developed, which is used during the construction phase. It is at this stage that the resource intensity of the process, the volume of construction and installation work, the amount of necessary equipment and materials, and therefore the final budget of the LAN project.Working documentation for the LAN is developed after approval of the previous design stage. The purpose of the work at stage "P" is to prepare accurate drawings, diagrams and tables that will guide installers when carrying out work on creating a LAN. Detailed documentation provides detailed linking of the components of all systems to the object. The working documentation of the LAN contains drawings, tables of connections and connections, plans for the location of equipment and wiring and other documents.
Estimate documentation for LAN (“SD”)
The development of estimate documentation is the final stage of designing a local computer network and determines the full cost of equipment, construction, installation and commissioning works.Construction (installation) of LAN
In accordance with the LAN project approved by the Customer and the purchase of the necessary equipment, the following is produced:GREEN EFFECT specialists provide a full range of LAN installation services.
The experience accumulated in this area allows us to install and connect a LAN in the shortest possible time, in strict accordance with the project and the proper quality of work.
LAN setup
Upon completion of installation, the LAN undergoes comprehensive testing and configuration in order to check the functionality of the system and identify defects. The results of testing and configuration with explanations of parameter values and an analysis of the quality of the local computer network are provided to the customer (an example of a testing report in the figure). After completion of all work and transfer of documentation to the customer, representatives of the contractor and the customer inspect the facility. If all necessary requirements and tasks are met, as well as compliance with the technical specifications, the facility is put into operation.
LAN maintenance
Maintenance of LAN (local area network) carried out to ensure uninterrupted operation unified system IT equipment of the company and constant access of personnel to various information services.LAN maintenance is carried out by diagnosing the condition of all sections of the LAN, taking measurements in cross-cabinets, detecting and repairing damage to LAN elements.
LAN maintenance includes:
The scope of LAN maintenance work depends on the operating conditions and the composition of the equipment.
Preventative maintenance work for LAN:
Diagnostics of LAN ports consists of measuring the parameters of LAN ports for compliance with category parameters using appropriate certified instrumentation with issuing reports on all measured parameters over the entire frequency range. Non-compliance of LAN ports with categorization requirements is determined based on the results of port diagnostics.
Restoration work of LAN maintenance:
Malfunctions identified as a result of preventive maintenance are eliminated by the Contractor as part of LAN maintenance. Depending on the nature of the fault, a decision is made to remove the faulty equipment from use and include it in the plan. current repairs LAN, or eliminating the defect on site. Malfunctions that require elimination additional work and material resources, be eliminated after drawing up a defective statement. Identified violations of LAN operating conditions are reported to Customer representatives.
The LAN maintenance work schedule is developed and approved by the Customer. Based on the results of the work, the contractor provides a report, which includes:
The bundles of wires hanging from the walls in the corridors of public buildings have sunk into oblivion. Now communications are laid hidden, in boxes, trays behind suspended ceilings, through switching floor cabinets to server equipment centers. All terminal socket devices are tightly fixed in their places, in walls or boxes, marked and numbered, the networks themselves have become local, performing a specialized role among separate group information devices.
How local networks are built
Modern networks are convenient to use, nothing “goes away” in them, you can easily integrate various even new applications into them and change their purpose. The cable infrastructure itself, or local area network (LAN), serves long years, for example, by changing active equipment that becomes obsolete much faster, you can easily increase throughput capabilities without major investments and capital expenditures. All this is preceded by the design of local networks, which determines the type and purpose of future local area networks. They set up a LAN not only for a group of computers united by one task, but also for local or separate applications. There are a large number of purposes for which a LAN is built, and a correctly formulated technical specification (TOR) will help the designer realize all the customer’s wishes. The LAN project must describe the infrastructure being created very clearly and in detail. Detailed floor plans indicate the location terminal devices, computer sockets, their purpose, numbering and marking, cross-connection diagrams, model and brand. During the construction of a LAN, various materials and equipment can be used from different or from a specific manufacturer; the choice of these elements and systems is also determined by the LAN project.
But not everything is as easy and simple as it seems at first glance; there are certain risks. For example, a technical specification (TOR) should be an integral part of the contract for design and survey work. The design company must have many years of experience in this field, have the necessary licenses, certificates and approvals, that is, be verified and professional. A very large number of amateur enthusiasts undertake work not only without design, without preliminary research of the object, but also without pre-agreed schemes, plans and work schedule. This results in additional work, increased deadlines, dirt and noise in the office, and a lack of clear understanding of the customer’s needs.
The cost of designing a LAN is negligible compared to the consequences of eliminating incorrectly performed work, incorrectly laid or completely unsuitable cable.
Capital investments made once in the cable infrastructure, in particular in the LAN device, will pay off many times over in the first year if you followed the right path: contacted a specialized company, for example, us, Engineering Group LLC. Already at the stage of creating the technical specifications, we will be able to reduce the Customer’s budget and time, we will come to inspect the facility (visiting the Moscow region is free), we will help you correctly formulate the technical specifications and tell you about innovations in this area.
Having ordered and received a competent LAN project, you can bring it to life with the help of any professional installation company. But if you order from us and complete the work, we can return some Money(up to 30%) spent during design.