Practical work number 23-24

Subject: The local network. Topology of local networks.

Purpose of work: apply in practice knowledge of appointment, principles for the construction and operation of local computer networks.

Theoretical information

Local computer network This is a complex of software and devices that combine subscribers who are at a slight distance from each other. As a rule, such systems are used within the boundaries of one enterprise or building.

Types of local networks

These lines are taken to divide on 2 types:

Networks for which the centralized management characterized by the General Security Policy Applicable to All Users

Peer networks. In such a system, all users independently determine what information and resources they will be submitted for general use. And computers are completely equal and can be simultaneously both by the client and the server.

The main tasks of local computing networks

the main tasklocal computer network - This is the implementation of joint access of all users to data, devices and programs. Thus, the system clients are available to perform operations at the same time, and not alternately.

In addition, local lines solve questions:

Processing and storage;

Transmission of information results to users;

Control of project implementation.

The main components of the local network

The local computer network cannot fully function without special equipment. For her, the main components are:

Passive equipment: Switching panels, mounting cabinets, information sockets, cables, cable channels;

Peripherals and computers: printers, servers, workstations, scanners;

Active equipment: Routers, switches (switches), special media intervectors.

Depending on how the network is built, what length and according to what requirements, the complex of devices during installation can change significantly.

Advantages of using a local network

This type of system solves many computational and informational tasks within one enterprise. Therefore, to organize a local-type computer network is necessary for several of its advantages:

The system provides all personal data on the file server disk. This makes it possible to simultaneously work with all clients, update data in network software products and at the same time use information protected at the level of files and directories.

The local network contributes to the exchange of information between all computers in the system.

Each client has access to a global network subject to the presence of a special switching unit.

This computing network provides full print information by all users on public printers.

The local system allows you to store software products (graphical editors, tables, database management systems) on file server disks in a single instance.

Requirements for local computing networks

CurrentlyIT companies A large number of locally computing networks have been created, which differ in the work algorithms, the structure of the organization, topologies, sizes. They are operated in different countries of the world, but the requirements for them are generally accepted.

Reliability. One of the main properties, aimed to save the full and partial function in the breakdown of several nodes.

Speed. The most important property characterized by the presence of high-speed data transmission channels.

Adaptation. The property of the locally computing network, aimed at expansion: workstations are installed in the place where it will be required.

The local network is an important element of any modern enterprise, without which it is impossible to achieve maximum productivity. However, to use the capabilities of networks at full power, you need to adjust them correctly, taking into account the fact that the location of the connected computers will affect the performance of the LAN.

The concept of topology The topology of local computer networks is the location of workstations and nodes relative to each other and the options for their compound. In fact, this is a LAN architecture. Accommodation of computers determines the technical specifications of the network, and the choice of any type of topology will affect:

Varieties and characteristics of network equipment.

Reliability and ability to scale LAN.

Local network management method.

There are many such options for the location of the working components and the methods of their compound, and their number increases directly in proportion to the increase in the number of connected computers. The main topologies of local networks are the "star", "tire" and "ring".

Factors that should be taken into account when choosing a topology

D.
on how to finally determine the choice of topology, it is necessary to take into account several features affecting the operation of the network. Relying on them, you can choose the most appropriate topology, analyzing the advantages and disadvantages of each of them and the current data with the conditions are available.

The performance and serviceability of each of the workstations connected to the LAN. Some types of local network topology are entirely dependent on this.

Feed equipment (routers, adapters, etc.). The network equipment breakdown can both completely disrupt the work of the LAN and stop the exchange of information with one computer.

Reliability of the cable used. Damage will violate the transmission and receiving data throughout the LAN or by one segment.

Limiting the length of the cable. This factor is also important when choosing a topology. If the cable is in the presence of a bit, you can choose this method of location in which it will need less.

On the topology "Star"

This type of workstation location has a dedicated center, the server to which all other computers are connected. It is through the server that the data exchange processes occur. Therefore, it should be more complicated.

D.
ostimity:

The topology of the local networks "Star" is favorably different from other complete absence of conflicts in the LAN - this is achieved at the expense of centralized management.

A breakdown of one of the nodes or damage to the cable will not have any influence on the network as a whole.

The presence of only two subscribers, the main and peripheral, allows you to simplify network equipment.

The accumulation of connection points in a small radius simplifies the network control process, and also allows you to increase its safety by restricting foreign access.

Disadvantages:

Such a local network in the case of a central server failure is completely inoperable.

The cost of "stars" is higher than other topologies, since cable is required much more.

Topology "Tire": easy and cheap

IN
This method of connection All workstations are connected to a single line - a coaxial cable, and the data from one subscriber is sent to the rest in the seduplex metabolism mode. The topologies of local networks of this species imply the presence of a special terminator at each end of the tire, without which the signal is distorted.

Dignity :

All computers are equal.

The possibility of easy network scaling even during her work.

The failure of one node does not affect the rest.

Cable consumption is significantly reduced.

Disadvantages:

Insufficient network reliability due to problems with cable connectors.

Small performance due to channel separation between all subscribers.

The complexity of managing and detecting malfunctions due to parallel adapters included.

The length of the communication line is limited, because these types of local network topology are used only for a small amount of computers.

Characteristics of the Topology "Ring"

T. aCI The type of communication involves the connection of the working unit with two others, data from one of them are received, and the second is transmitted. The main feature of this topology is that each terminal acts as a repeater, eliminating the possibility of attenuation of the signal in the LAN.Advantages:

Fast creation and configuration of this topology of local networks.

Easy scaling requiring, however, stop the network operation during the installation of a new node.

A large number of possible subscribers.

Resistance to overloads and lack of network conflicts.

The ability to increase the network to huge sizes by relaying the signal between computers.

Disadvantages:

Insecurity of the network as a whole.

No resistance to cable damage, therefore, it is usually provided for the presence of a parallel backup line.

Large cable consumption.

Types of local networks

The choice of local network topology should also be made based on the existing type of LAN. The network can be represented by two models: peer-to-peer and hierarchical.

They are not very different functionally, which allows you to move from one of them if necessary. However, several differences between them are there. As for the peer-to-peer model, its use is recommended in situations where the possibility of organizing a large network is absent, but the creation of any communication system is still necessary. It is recommended to create it only for a small number of computers. Communication with centralized management is usually applied at various enterprises for monitoring workstations.

Single Network

E.
the type of LAN implies equality of each workstation, distributing data between them. Access to the information stored on the node can be allowed or prohibited by the user. As a rule, in such cases the topology of local computer networks "tire" will be the most suitable.

Single network involves the availability of workstation resources to other users. This means the ability to edit the document of one computer when working after other, remote printing and starting applications.

Advantages of peer-to-peer type LAN:

Ease of implementation, installation and maintenance.

Small financial costs.

Such a model eliminates the need to buy an expensive server.

Disadvantages:

The speed of the network decreases in proportion to the increase in the number of connected work units.

There is no unified security system.

Availability of information: When the computer is turned off, the data in it will be inaccessible for the rest.

There is no single information base.

Hierarchical model

The most commonly used topologies of local networks are based on this type of LAN. It is also called "client-server". The essence of this model is that in the presence of a certain number of subscribers there is one main element - server. This managing computer stores all data and is processed.

Advantages:

Excellent network speed.

Unified reliable security system.

One, overall for everyone, information base.

Lightweight management of the entire network and its elements.

Disadvantages:

The need for a special personnel unit is an administrator who is engaged in monitoring and servicing the server.

Large financial costs for the purchase of the main computer.

The most frequently used configuration (topology) of the local computer network in the hierarchical model is a "star".

The choice of topology (layout of network equipment and workstations) is an extremely important point when organizing a local network. The selected type of communication should ensure the most efficient and safe operation of the LAN. It is important to also pay attention to the financial costs and the possibility of further expansion of the network. Find a rational solution is a difficult task that is performed due to careful analysis and responsible approach. It is in this case that correctly selected topologies of local networks will ensure the maximum efficiency of the entire LAN as a whole.

Exercise 1

Describe a peerbread local network with a linear bus topology.

Fill the table.

Local network scheme

disadvantages

Benefits

equipment

cost

Conclusions:

Task 2.

Describe a one-alone local network with a star topology.

Analyze the description of the local network and draw conclusions.

Fill the table.

Local network scheme

disadvantages

Benefits

Number of computers online

Equipment necessary to create a network and its cost

equipment

cost

The total cost of creating a local network

Conclusions:

Task 3.

Describe a local server based on the server.

Analyze the description of the local network and draw conclusions.

Fill the table

Local network scheme

disadvantages

Benefits

Number of computers online

Equipment necessary to create a network and its cost

equipment

cost

The total cost of creating a local network

Conclusions:

Decide on the starting moments: a small company, let approx 15-50 employees. As a rule, there is no qualified network specialist. And most likely it is "allocated" to work with the network, the network administrator on staff. Let us agree - your specialist is needed. And he needs to pay money, and - what good money (what is the horror, yes? Here is the news something for many directors). I will try in this article (perhaps with a continuation) to act as an administrator of a network of such a small firm. So, we build a network yourself. Why not? There are many arguments "against" the "self-assembly", and all of them are true (if, of course, this is not a frank "noodles" from a potential contractor). But, after all, you can and yourself. Arguments "For" also enough. We will not give them here - we believe that they decided to do themselves. We will do not make new-fashioned radio, Wi-Fi and other networks, but an inexpensive, but high-quality cable network of a traditional wired type for the daily work of the firm. However, it is necessary to understand that the work should perform a specialist (or several).

Introduction

Decide on the starting moments: a small company, let approx 15-50 employees. As a rule, there is no qualified network specialist. And most likely it is "allocated" to work with the network, the network administrator on staff. If there is a master of all hands, and often forced to engage in some "urgent" case like installing Windows or drivers to some computer, instead of working with the network. Together with other "computerists" (if any). Network works? Let the deck beyond the stump, well, well, a little later will take it (we will do it).

Let us agree - your specialist is needed. And he needs to pay money, and - what good money (what is the horror, yes? Here is the news something for many directors). I will try in this article (perhaps with a continuation) to act as an administrator of a network of such a small firm.

Initial data

So, we build a network yourself. Why not? There are many arguments "against" the "self-assembly", and all of them are true (if, of course, this is not a frank "noodles" from a potential contractor). But, after all, you can and yourself. Arguments "For" also enough. We will not give them here - we believe that they decided to do themselves.

However, it is necessary to understand that the work should perform a specialist (or several). It is impossible to train ("even bad, but yours") and raise your specialist in such a way. You can give a person to a person who performs the work (drilling holes by a perforator in the walls and the cable-channel attachment will not take into account - it should be able to be able to any man).

Another factor, add so to speak, "pepper" - our company, in addition to the office, has a store and a warehouse that are quite deleted.

We will do not make new-fashioned radio, Wi-Fi and other networks, but an inexpensive, but high-quality cable network of a traditional wired type for the daily work of the firm. For work, not for surfing with a laptop of news and / or porn sites from a hotel sofa. We may return to these questions in the continuation (not to the hotel and others with her, of course, and to modern technologies).

The last, and, also, very important: I consider money, but do not greading.

Plan

At the very beginning, it is necessary to make one very simple, but a very important thing - take a few sheets of paper, pencil and sit behind the draft business plan. It is very important to more or less clearly "take a pencil" all keywords that come to mind from the question "what I want from the network." These positions will draw on the first sheet. On the second - they are grouped according to separate categories. For example, the category "Services". What are the services we want to get from the network, and what quality? What do we need? File-, FTP-, PRINT-, INTERNET-SERVICE?

It would seem that everything seems to be clear, why write, draw? But, if you do not take everything on a pencil - then it will be worse. For example, it turns out that you need to go to the director and / or in the accounting department: "Sorry, we bought it here here, and not for 100 cu It is necessary, and for 500. ".

Now you can stand it to add what you need, throw out the excesses. And all this is postponing at least for the day. Next, the draft can be transferred to the third sheet. With "final" add-ons and corrections. Why quotes - you yourself understand, this is not the last leaflet, and far from the last "sketches".

Services - services, however, the base is an SCS, that is, a structured cable system. Let's try not to run very ahead of the horse.

Usually there are two options - the office "from scratch" and the office "ready". The first case is naked walls and ceiling, our repair is, and that's good. The second option is "ready." Those. - We begin the outer gasket of the SCS. But let's start not from this while.

Electricity

An important stage, because God will "fly" not just one or two ordinary computers, can "fly" everything. Well, we believe that in our office with a power network everything is in order. Here are only one important point - uninterruptible power sources (UPS). They are needed. Believe me. The diesel generator, of course, is good, but not in all cases is obligatory, but sorry the money to install the UPS to each server or the communication cabinet is simply stupid. However, we will return to the issue of UPS at one time.

SCS and basic active equipment

Structured cable system (SCS) is one of the cornerstone. SCS must be properly designed and built. We divide the question for items:

* Communication cabinet (with "stuffing")
* Cable lines
* Subscriber sockets

It is very useful to the plan of premises, with well-marked places of employees. It must be borne in mind - it is also not bad to note the power outlets. Next - in order, let's start with the cabinet.

Communication cabinet: We find a comfortable place to install a cabinet with equipment. It is important to find the optimal distance to workstations, in order to reduce the costs of vitua pair, cable channel and other "trifle". Factors Many: limiting the length of the line up to 100 meters (or rather, 90 meters, according to the classical formula 90 + 5 + 5); Office layout (in which place it is convenient to put or hang a wardrobe, it is convenient to pass the walls when the cable is broken, there will be no cooling to put on the ears to customers or employees, etc.); Actually, the design of the cabinet (floor, wall, its height in U, the number of equipment that needs to be installed in it whether the cooling unit will be).

Cabinets There are the most diverse, it is necessary to carefully check the prices and the quality of the intended purchase, do not forget to make a stock by capacity (!) In those u. Necessarily - the presence of at least one shelf. However, in some places it is quite possible to do with wall brackets, to secure equipment. But it is already specific. We assume that for the office we chose a 12-14-high-rise cabinet, with a glass door. Little run ahead, you need to mention what will be installed inside:

Shelf: It always comes in handy, even if it is empty (I doubt it) - it can be removed. It is not necessary to regret 10-20 dollars, when you have to "suddenly" put the device-other in the closet, remember these lines.

Switch (Switch): 24 ports on the lower limit of employees of the company in the office - let it be 10-20 people in the office (and do not forget about servers and other network equipment). However, if there is a big density of jobs, no problems add the required number of switches and other relevant equipment will.

Distribution panel (PATCH panel): 24 ports, all similar to the switch. It is on the patch panel that all lines from workstations and servers will be reduced.

Panel (block) of power outlets: By the number of connected equipment in the closet, plus - stock 1-2 outlets on the panel. Here we may well be waiting for an ambush if you have to connect power supplies - may not be enough (you remember about 99.9% of the market filled with network filters with tight-space planted sockets).

You can put a cheap simple version (this is when the shelf is useful, but you can also on the floor of the cabinet), you can and 19 "UPS, designed to install in the closet.

So, looking at the market offered on the market, we believe that with the cabinet it was determined: 14-altitude (14 U). For example, Molex Modbox II 14U:

The possibility of applying in the cabinet of the 19-inch fan 1U
. Standard cabinet equipment:
. Light steel profile provides a closet of greater rigidity and strength
. Aesthetic glass door with lock
. The door of the universal design with the ability to outweight (left, right)
. 19-Tijum Frame with Depth Regulation
. Grounding all cabinet elements
. Cable input holes are equipped with a protective brush to protect against dust penetration into the cabinet

Switch. His choice is a more difficult question. Very cheap switches do not want to consider. Devices are expensive (and very more expensive), but still you will have to choose from two types: unmanaged and managed.

I will stop the view on the following two devices: Zyxel Dimension ES-1024 and ES-2024:

It is a cost-effective solution of FAST Ethernet and can be used to build highly efficient switched networks. The intermediate storage feature significantly reduces the waiting time in high-speed networks. The switch is designed for working groups, departments or main computing environments for small and medium-sized enterprises. Due to the large address table and high performance, the switch is an excellent solution for connecting the networks to the corporate highway or to connect network segments.

Specifications:

24-port Fast Ethernet Switch
. Compliance with IEEE 802.3, 802.3u and 802.3x standards
. RJ-45 Ethernet ports with automatic 10/100 Mbps speed selection
. Automatic Definition of the Cross Cable Connection on All Ethernet Ports RJ-45 10/100 Mbps
. Back-Pressure-Base Street Control Support for Half Duplex Ports
. Pause-Frame-Base flow control support on full-duplex ports
. Communication support with intermediate storage
. Support for automatic address definition
. Maximum shipping speed via wired network
. Built-in table of MAC addresses (8K MAC address)
. LED power indicators, LK / ACT and FD / COL

Application of the ES-2024 switch Allows you to combine a group of users and connect their high-speed lines to the corporate network. Additionally, it will be possible, thanks to the use of iStackingTM technology, combine a group of switches to control the network, regardless of their location.

Specifications:

24 RJ-45 ports with automatic selection of 10/100 Ethernet speed and automatic definition of cross-cable connectivity
. 2 ports 10/100/1000 Ethernet
. 2 Mini-GBIC Slots Combined with Ports
. 8.8 Gb / s Noked Switching Tire
. Support for IEEE 802.3u, 802.3b, 802.3z, 802.3x, 802.1d, 802.1w, 802.1p
. Table MAC addresses 10kb
. Support VLAN: Port-based and 802.1q
. The ability to limit the speed on the port
. 64 static VLANs and up to 2kb dynamic VLAN
. Mac filtering addresses
. Support for ZyXEL IStacking ™, up to 8 switches (in the future up to 24) managed at one address IP
. RS-232 control and web-interface
. Telnet Cli.
. SNMP V2C (RFC 1213, 1493, 1643, 1757, 2647)
. IP Management: Static IP or DHCP Client
. FTP firmware update
. Update and save system configuration
. Standard 19-inch Stand Mounting

As you can see - there is a difference, and very serious. As is the difference in price - approximately 100 and 450 dollars. But, if the first switch is decent, but "stupid" box, then the second is in some sense of intellectual, with much greater functionality and manageable, with potentially strong parties. We choose the second option. After all, we want to build a good network?

By the way, it is now quite time to ask the question why, in fact, we build a network "weaving"? Now in each second computer is not just a gigabit network interface, but two gigabit?

This is the case where you can safely save. The fact is that the operating office of the 100-megabit network is more than enough. If there is also a decent switch! Yes, and two gigabit interfaces of the selected switch - boldly "Sadim", for example, two servers. Here they are, servers, it's just good.

Of course, you can take something like Zyxel GS-2024 and plant everyone on a gigabit channel, but this is just the case of unreasonable spending money, and for such money we can buy a fully equipped wardrobe with a more complied with a stuffing.

Patch panel. Also the case when you should not save much. Select the panel like Molex 19 "24xRJ45, Katt, 568B, UTP, PowerCat 5E, 1U.

Compliance with the requirements of category 5e. The compensation system is implemented directly on the printed circuit board. The use of type connectors is accelerating and simplifies the installation of the cable. Dedicated place to marking channels. The panel is covered with powder varnish. All necessary fastening and marking elements are supplied complete.

There are many options, as already mentioned, you can put any cheap, it is expensive, you can, you can 19 "Rack-option - there will be beauty. Who does not know the company APC? You can see for example such a UPS:

APC Smart-UPS SC 1500VA 230V - 2U RACKMOUNT / TOWER

Or, here's the following:

Do not deepen in the characteristics, we note that many devices are completed on request guides for installing the UPS in 19 "Rack. Also, there is an opportunity to complete, at will, the SNMP module for monitoring and managing the UPS on a computer network. Of course, it will cost money, but It may be very convenient. You will choose your choice on IPPON. It should be noted that the SNMP support can be equipped with a model 1500, 2000 and 3000, and 750 and 1000 - no.

Power outlet block:

Without special comments - maybe you can find something and cheaper, easier. But dozens of "suffocked raccoons" will not make the weather.

It remains not to forget to make a solution whether the fan unit is required in the closet? Expensive pleasure, especially in a pair with a block of thermostat. However, we will take it to the specifics of the place / office.

With the cabinet more or less figured out, all sorts of "trifles" remained, without taking into account which will be annoying delays:

* Screws with nuts for mounting equipment in the cabinet;
* Nylon non-opening ties for laying and fastening the cable (packs of 100 pcs. Length 100, 150, 200 mm);
* Marking for the cable (adhesive sheets with a protective layer).

In fact, we got to the SCS itself. Very important "detail" - a cable that will be given a SCS layout. Yes, again the call is not saved. A good twisted pair is a good attachment. We take Molex, unshielded UTP PowerCat 5E cable.

The cable is the main element of the PowerCat product line. The line is designed for use in high-speed telecommunication networks (for example, Gigaethernet 1000Base-T).

To subscriber sockets, we, of course, come, and then? Next - to buy the required number of patch cords to connect workstations. Naturally, we need to consider the length, look at the I mentioned the office plan. But that's not all. We also need strainded cable (normal - Solid). This is a special twisted pair, "soft", from which the patch cords are made. After all, it will be necessary to quickly or later the patch cord is needed, rather than it is from ready-made at hand (if it remains at all time). In addition, it is possible (or It is necessary - as you wish) will be made short - 30-50 cm, patch cords for crossing the SCS lines and active equipment in the closet itself. Therefore, "take a pencil" another pair of packages of the RJ45 connector, in the spacious - "chips". And Packaging of rubber caps for them. The caps are better to take soft and with a slot to the lock "chips", and not with the "pupid" under the lock.

We have already reached almost to the network interfaces on custom computers, but still need subscriber sockets. Someone against such a wonderful thing like Molex Office Block 2khrj45? ;-)

Compliance with the requirements of category 5e. Modules are designed for high-speed telecommunication networks. The ability to enter a cable from sides, top or rear. Standard modules are equipped with dust curtains. Convenience of labeling channels. Built-in magnet simplifies mounting modules to metal surfaces. The possibility of fastening with screws. Fastening the cable inside the module without cable clamps. Free sequence sequence (568A / B). Connector type "Catt" facilitating installation. The kit includes mounting items. .

It is necessary to determine here. After all, there are single options. We take the office plan again. In determining the installation locations of the sockets, there is another important point - a self-seller to add one or two additional SCS. One - just "just in case." What if there will be a little planning in the office or someone will need to connect a laptop? The second is not bad to have a printed server, to organize a network printing. It is very nice to have a cabinet or office one or two network printers that work without problems and whims of the host (or Windows).

Do you think - all? Not. Another factor is forgotten by any office telephony. To think very good about this: if telephones should be held to some workplaces, then why not make a wiring in the general SCS? After all, the question can be solved simply: throw a line-other to the necessary places, put a rosette next to RJ-45 and RJ-12, you can even in one case (block). In the outlet - DECT, for example, with several tubes, and in the closet, we carry out a line (lines) from the PBX - they can be placed on the sockets, neatly glued with velcro inside and side. Lines from jobs - on them.

It seems time to take for cable-channel and dowel-nails? Yes. It is time. But this is already clear a man with a hand, we will not stop at this long time. Just need to take into account the number of stacked lines in the cable channel. And, of course, a small supply is needed. Very good, if in the office of the suspended ceiling, the lines can be stretching behind it right to the workplace and drop in the Cable Channel on the wall. When stretching lines, flashed nicely (as in the further sockets). The easiest method is the first outlet to the left of the door - №1, then in a circle.

Stretching the line, you can proceed to the splitting of the patch panel and sockets. Overly to say, this work requires accuracy and qualifications. It is at this moment that we will use the labeling of lines - if all lines split in order, then in the future operation of the SCS can be almost done without a card (layout) of installation, approximately such:

Socket

However, this card is still needed in the future. It will be useful.

When laying cables, some simple rules must be observed (it is simple, we will not delve into standards and other ISOs now):

* Do not bend strongly, do not rub and do not step on the cable. Cable bending is allowed: when installed - 8, and, during operation - 4 radius of the cable itself;
* Do not lay the lines next to the power: if there is a need to put in parallel - at a distance of at least 20 cm;
* Cross the power lines is allowed, at right angles;
* Be sure to test the cable tester.

Separately about the last paragraph. Remember the anecdote about Japanese delivery of something there? "Dear customers! We do not know why it is to you, but we still decided to put in boxes on one defective chip for every ten thousand, according to your requirements. " Yes, you can just split and forget. An experienced installer is not mistaken. However, really an experienced installer will surely check, and not only the layout of the line, but also the quality.

So we reached the very interesting moment. If we check the trifle simple and cheap tester, then there are no tests and certification of lines - no, it will not work.

Which exit? I really do not want to leave the question of the quality of the lines unresolved. There are three options. First - buy a good tester, for example:

But, alas, we are very sorry for $ 6,000, let it even for such a beautiful and necessary device.

This is a compact portable tool used for certification, testing and detection of faults in a coaxial cable and a cable based on twisted pair in local computers. The tester is recommended by leading manufacturers of information cable systems for testing for certification of systems to class E inclusive. The high level of reliability, convenience and accuracy of the device provided it one of the first places among the products of this class. For rapid and high-quality testing of cable connections in the extended frequency range up to 350 MHz, digital signal processing technologies are used.

The second option is to invite a familiar admin or installer who has such or similar device. Of course, after purchasing a box of good beer. Half an hour work, plus beer evening in a pleasant company friend.

The third option is to officially invite specialists from any firm that provides such services. And pay these services. It is not so much, especially if you do not require a certificate on paper.

Remote workstations

"Having finished" (quotes because they need to first plan everything and make the necessary purchases and negotiations) with the works on the main office, we remember about a warehouse and shop.

Now (in these notes) Consider not a "wisdom" solution like VPN, and the simplest is the organization of communication of computer networks with subnets (workstations with the network) by the dedicated line. Effectively, cheap and angry. By the way, it is highlighted, of course, you should start to the closet and connect to sockets, like the phones.

If the distance and, accordingly, the resistance of the dedicated line is small, you can try to put a pair of "Bridge", for example, already mentioned by Zyxel Prestige 841c and Zyxel Prestige 841. Model "C" - "Master", so this device is better installed in the head office. These are inexpensive devices working on VDSL technology, but provide the necessary results for our task. What says zyxel:

Depending on the type and condition of the cable, as well as from Prestige 841, a pair with Prestige 841C provides the following data exchange rate:

Towards the subscriber - ranging from 4.17 to 18.75 Mbps
. in the direction from the subscriber - from 1.56 to 16.67 Mbps
. The total bandwidth of the line can reach 35 Mbps

Specifications:

Ethernet VDSL Bridge
. Connection of local networks at a speed of 15 Mbps to 1.5 km
. Plug & Play transparent for all protocols
. Work in a pare
. Desktop execution
. Non-volatile memory (Flash ROM)
. Size: 181 x 128 x 30 mm

This option will give 18 MB in each direction, ideally, of course. This is VDSL.

When using Prestige 841 there is another plus. These devices have a built-in splitter, and we can get a "free" telephony with a remote place. It is enough to turn on the phone of the remote workplace in the phone "phone" on one side, and on the other hand, connect the office mini-PBX.

If Breeches VDSL do not "stretch out the line, you need to look at other devices, XDSL. For example, something from the 79x ZyXEL series, SHDSL.

Optimization of the hardware and the use of advanced technologies allowed not only to reduce the dimensions of the device, but also reduce the cost and improve the functional characteristics. Provide a symmetric connection at speeds up to 2.3 Mbps and can operate on a selected 2-wire line as in the point-to-point mode, and as a client of the Internet provider concentrator.

Specifications:

. SHDSL router
. Support G.991.2 at speeds up to 2.3 Mbps symmetrically
. Network connection or Internet access at large distances
. Encapsulation PPPOA, PPPoE, RFC-1483
. TCP / IP Routing, Full Nat, Package Filtering
. Support IP Policy Routing, UPNP, connection reservation
. Management through the console, Telnet, Web, SNMP

Ideal speed - 2,3MB for two wires. If "charge" 4 wires, the speed will be, respectively, more. However, these devices will cost much - 400-500 dollars per pair. In any case, roughly speaking, the worse the quality of the line, the lower the speed and more costs. However, the configuration (tuning) of devices will postpone the future, this is a separate conversation, especially since it does not have too large for VDSL 841. XDSL devices should be put on the shelf in the closet. After all, I said that she would not be empty.

Internet connection

Zyxel Prestige-660

Modern office is unthinkable without internet. For connection we can use ADSL technology, for example - Zyxel Prestige 660.

As the ZyXEL device describes:

Modem P-660R It belongs to the fourth generation of ADSL modems and combines the functionality in one device necessary to connect an existing office or home network to the Internet: ADSL2 + modem, router and firewall. The modem will provide your office with a constant connection to the Internet, working quickly and safely. Installation and maintenance of the P-660R modem is simple and will not deliver any problems even unprepared users.

The main advantages of Zyxel Prestige 660:

* High-speed Internet - up to 24 Mbps
* Reliable connection on problem lines
* Free phone
* Permanent connection
* Does not require driver installation
* Works with w



Local Wired Network (LAN) is the basis of home information space and multimedia .. Criteria for building LAN .. Wireless connection - pluses and cons .. Fast Ethernet technology .. Structural scheme LAN-Network .. Network Topology "Star" .. Choosing equipment LAN -set .. router (router) .. Routher setting .. Built-in ADSL modem .. Wi-Fi access point .. switch or hub? .. D-Link DSL-6740U characteristics .. Specifications D-Link DIR-615 / K1A .. UTP CAT 5E cable (dual twisted pair) .. Technical task.. An example of a local network project .. Equipment arrangement scheme .. Mounting diagram LAN-network.

Today it is impossible to imagine a house, an apartment or an office without numerous complex devices and devices, communicating with which in our time is already becoming a problem.
A person voluntarily enaches dependent on computers, Internet, audio and video systems, consoles, security systems and other electronic devices that give us new features and convenience, but take away all your free time.
To cope with this problem and make life as convenient and comfortable, you need to set new tasks that can be implemented using the smart home technologies.

The most popular in the modern house are the following systems:

Wired local network
Multimedia
Lighting control
Heating and microclimate control
Security and fire alarm
CCTV
Intercom and access control.

Implementation of "smart" systems It may be complex (in the case of overhaul or construction of a new house) or partial.
It all depends on the priorities of the choice of certain systems and the possibilities of their implementation.
Today we consider a wired local network.

Wired LAN (LAN)


Wired Local Network (Local Area Network) It serves to centrally connect to the Internet and the connection of computers and various peripheral devices in the house among themselves. In fact, the local network is the basis of home information space and multimedia.

Designed and building a computer, telephone and television network in your homeYou will provide the necessary communications all multimedia and computer equipment in the house.
It always makes sense to consider and designing these networks together.

Why wired.
The choice is always yours. I just emphasize that when there is a possibility, You need to choose wired technologies.
At a convenient case, I try to justify this choice.

Wired and Wireless Connection: Pros and Cons

From the plus Wireless equipment can be noted a large number of connections, which is limited only to the transmission rate per user. More - the ability to connect mobile devices (smartphones, communicators, tablets), as well as freedom of movement indoors. Perhaps, that's all.

Minuses: Wireless technologies are usually more complex in the device and, accordingly, less reliable than wired. For an unqualified user, this may result in difficulties during operation, in particular, in diagnosing and troubleshooting. This is especially true with increasing the number of devices.

Wireless connection will be less high-speed.
No one will argue that the technical indicators of the signal level over the cable are higher than the radio signal. The speed of the wireless communication is inferior to wired almost twice both by objective reasons (wireless data protocol is slower) and due to external interference (metal fittings of the walls, interference from home electronics, etc.).
There will always be an technique that is demanding about the speed and quality of the connection - for example, the same multimedia HD-media players, information from which can be requested from several devices (computers, televisions, etc.) If you want to watch the Bluray Quality Movie on the high-resolution projector , Then the speed of Wi-Fi using even modern equipment may not be enough.

Price Wireless equipment will cost half a half more expensive than its wired analogues.

Electromagnetic "Pollution" And the mutual interference of the wireless equipment also no longer canceled.
Therefore, before using the Wi-Fi wireless network connection, you must weigh all the "for" and "against" and make sure that it is impossible to do without wireless equipment.
Perhaps, it is better to minimize harmful radiation in the workspace, where you spend a significant part of the time.

On practice Home Local Area is most often combined. For example, stationary computers can be connected to the network using the wires using Ethernet technology, and various mobile devices (laptops, tablets, smartphones) are via Wi-Fi wireless standard.

Criteria for building LANs

When choosing a network standard and network topology the decisive factor is the data transfer rate and the possibility of further expansion of the system. These conditions are fully answered by the wired Ethernet technology.

This standard Provides parallel data transmission. This means that in Ethernetdata is transmitted not to all devices alternately (as in RS-485), but directly the desired device. This significantly increases the speed of information transfer. In addition, this protocol provides compatibility with existing network devices and future developments. Using the protocol Ethernet, It is confident that the local network being under construction will be able to get development in the future.
Currently, there are three specifications that differ transmission rate:

Classic Ethernet (10 Mbps);
Fast Ethernet (100 Mbps);
Gigabit Ethernet (1 Gb / c).

For home information network The most optimal value for price / quality / complexity is the topology "Star" and the network standard 802.3 100Base-TX. This is a 100 megabit Ethernet on a dual twisted pair, which in terms of price / performance while out of competition.

The basis of the network is the switchTo which the network devices are connected by cables with a maximum length of 100m.

Big plus topology "Star" - Its scalability, that is, further expansion, namely, it is very important in home networks. This is achieved by the fact that each computer (or other device) connects to the ethernet port or switch dedicated for it. That is, one port of the switch is one computer. Typically, the number of the Ethernet port ports is selected with the reserve, so there is always the possibility of connecting a new device to the spare port. Accordingly, each computer must be equipped with a network adapter with the RJ-45 connector.
The task is facilitated by the fact that all modern computers and laptops already have a built-in Ethernet port connector.

Criteria for choosing equipment

All homemade local networks are arranged according to one principle: User computers equipped with network adapters are connected to each other through special switching devices. In this capacity can perform routers (routers), hubs (hubs), switches (switches), access points and modems.

Routers

The main component of the home LAN is the router or routerwhich is a multifunctional device with a built-in operating system having at least two network interfaces:

1. LAN (Local Area Network) - Used to create an internal (local) network, which consists of your computer devices.
2. WAN (WIDE AREA NETWORK) - Used to connect the local network (LAN) to the world global network - the Internet.

Routers are divided into two classes By type of external connection: Ethernet or ADSL. Accordingly, they have a WAN-port or ADSL port for connecting the provider cable to four LAN ports to connect network devices using Ethernet technology.
The router for connecting to the ADSL line has a built-in ADSL modem.

Wireless routersbesides other, have built-in Wi-Fi access point To connect wireless devices. The number of equipment that receives simultaneous access to the network using Wi-Fi technology may, in principle, are calculated dozens. Taking into account the fact that the channel frequency band is divided between all connected clients, the bandwidth of the communication channel decreases with an increase in their quantity.

When the number of connected computers does not exceed four, the router turns out to be the only component that is necessary for building a local network, since the rest is simply no need.

When choosing a router For home network preferably router using technology IEEE 802.11n.which provides better performance and signal coating. In addition, these routers support the user's VPN mode and have a built-in USB port that can be used to connect a flash drive, printer, or an external hard disk (NAS).

Before buying a router You need to clarify the provider in advance, which type of connection you will use, and what additional equipment you need for this. The supplied routers must include an external power adapter and the RJ-45 cable, and for models with ADSL port, the RJ-11 cable and splitter.

Useful consult with technical support provider For technical requirements for client equipment, in terms of its compatibility with the provider servers. Having received professional information, you can easily make your choice from available on sale models of routers.

On the number of equipment. If you design a local network for a 2 or 3-storey cottage, then one Wi-Fi router can not do. To ensure a sufficient level of the wireless signal, you will have to build a distributed Wi-Fi network consisting of several routers or access points. To reduce the load on the wireless network and increasing the data transfer speed, you can only leave Wi-Fi access for mobile devices, and computers (possibly and laptops) are organized on wired access.

Another moment: Today to buy a router without the support of Wi-Fi is simply meaningless. The difference in the cost of a good wired router and its wireless analogue is very small. Even if you in the near future do not plan to use the Wi-Fi module in the router, then it can be turned off. When you have such a need (for example, a device with Wi-Fi connection will appear at home), you can always turn on the Wi-Fi module in the router and start using wireless Internet.

About setting up router

On the Internet there are quite a lot of recommendations for setting up routers, Including detailed instructions for specific models. Here I want to note the following:

Given the interests of usersThe developers have long facilitated the setting of router parameters using the built-in for step-by-step setting by making it accessible even for beginners.

In most cases, during the first login in the router menuThe launch of the wizard, which offers a quick step-by-step setting of its basic parameters. It eliminates novice users from searches for the desired options among numerous menu sections.
If necessary, the installation wizard can be started manually using the menu item in different options: Quick Setup (Fast Setup), Setup Wizard (Installation Wizard), etc.

One should only considerIn certain situations, connecting to the Internet may require special settings, the possibility of entering which is simply missing in the Master mode. In these cases, you will have to refer to the manual setting mode of the parameters.

Switches

If you want to build a more extensive wired network, then four LAN-ports of the router will not be enough. In this case, an additional switching device is connected to one of the router ports - concentrator (HUB) or switch (Switch).

Unlike router, switches and hubs have only one network interface - Lan. and are used only to scale (expansion) local networks.

To create a wired Ethernet network It is better to use the switch (switch), not a hub (hub). The switch analyzes traffic emanating from computers and directs it only to the one who is intended. The hub simply repeats any traffic to all ports. As a result, the performance of the Ethernet network at the hubs highly depends on the total load. The network on the switch is free from this shortage.
Previously, it was necessary to choose: or price, or performance, since the hubs were significantly cheaper than switches. Now both types of devices are almost equal in price, so the choice in favor of the switch is no doubt.

Which switch to choose?
Currently, there are many models and types of network switches, their price and functions are very different. When choosing, it is necessary to proceed from the minimum cost of the device, which will meet your data transfer rates and the number of ports. Also, the dimensions of the switch may also have.

Speed \u200b\u200bof work
For a home local network, the price / performance ratio is optimal yet Fast Ethernet remains (100 Mbps).

Number of ports
This indicator characterizes the number of network devices that can be connected to this switch. In many respects, this parameter determines the price of the device.
The choice depends on the number of users of your future network. To the number of users it is necessary to add 1-2 ports about the reserve.
In models oriented on home use, the number of Ethernet ports is usually equal to 5 or 8. If at some point to connect all devices for the number of the switch ports, it will cease to be enough, another switch can be connected to it. Thus, it is possible to expand the home network as much as you like.

Cables

As a transmission medium 100BASE-TX (Fast Ethernet) Applied unshielded cable UTP Cat 5e (dual twisted pair), and one pair is used to transmit data, and the second is for their reception. It is possible to use Cat 5e Cable type 100Base-T4 (quad twisted pair): Two backup pairs can be used to upgrade the network to the level of 1000 Mbps (Gigabit Ethernet).

Shielded Cables (FTP, STP, SFTP) Applied when laying trunk lines and in industrial premises with large electromagnetic fields. In domestic local networks, as a rule, an unshielded UTP cable is used.

For telephone network Cable applied UTP Cat 3. (dual twisted pair).

Is it possible to use a phone to save one of the four-party cable pairs used for computer networks?
It is possible, but hardly you need. Why create yourself additional problems with installation. It is best to apply a separate not shielded posting with a twisted pair, as it significantly increases telephone interference. In addition, the backup twisted pair of CAT 3 cable in the future can be useful for repairing a damaged pair or to connect an additional apparatus.

Village couples in cables there are two species, from a single conductor and stranded. The diameter of the veins in single-core vita pairs is 0.51 mm. Cables with single-cable conductors are used to mount networks in boxes, cable channels and walls. With multiple conductors, the cable is applied only where it can be exposed to frequent bends, for example, to connect the computer with RJ45 socket (patch cord).

In accordance with the Topology "Star" All cables from network devices converge to the switch, and at opposite ends of the cables are installed sockets with RJ45 jacks. Both cables and sockets should be categories 5e or 6.
All cable segments should be no more than 100 meters - only in this case is guaranteed steady operation of the network. It is necessary to take into account the fact that the requirement for the maximum length of the cable segment in 100 m includes the entire length of the cable connecting the computer with the switch. If the cable wiring ends on the computer side of the wall outlet, and on the side of the switch - the crossbar, then the switching cables connecting the computer with the socket and the cross-panel with the switch in the length of the segment.
It is recommended to take the maximum length for the internal layout cable segment, equal to 90 m, leaving 10 m for switching cables.
Of course, all cables must be solid, no "scrubs" are not allowed.

Example of a local network project

The basis of creating any project is the technical task (TK).
Ideally, the detailed technical task for design should provide the customer. In practice, especially for private households, the designer in fact has to participate in the collection of source data and the development of TK, since without a complete understanding of the features of the object and consultation with the Customer, it is impossible to fulfill the project.

Sample designer action sequence When drawing up a technical assignment to the design of the "smart" house, it was considered in detail in the article "From the classic electrician to the smart home" .

Consider the actions of the designer Based on the TK coordinated with the customer for the design of a local network for a two-storey country house with an area of \u200b\u200b200m2.
As noted, computer, telephone and television networks are combined in one project.

Initial data

1. There is a package plan at home.
2. High-speed Internet access - on the dedicated ADSL line
3. Access mode to urban PBX - Pulsed
4. Number of Ethernet sockets - 6
5. Number of telephone sockets - 1
6. Must be provided:
Wi-Fi Access Points for connecting wireless devices.
Spare port for an additional wired connection 1 computer.
7. Television: Essential + Satellite TV
8. The number of TV sockets + SAT - 6

Playing equipment

Although it is a relatively small local network.But taking into account the equipment of telephone and television networks and two levels (floors), it makes sense to use mounting low-voltage cabinets, and for connecting network devices, the corresponding sockets. It is convenient to use the network socket because when changing the location of the computer (or TV), you do not need to lengthen the entire cable segment - just create a new patch cord connecting the device with a socket.
On the plan of the house The places of intended placement of mounting cabinets, computers, phones and television receivers are determined.
Placing equipment on the 1st floor plan is shown on fig.1.

Fig.1


Choosing equipment

Internet connection It will be carried out by the dedicated ADSL channel in the telephone line leading from the PBX to the house. This means that when choosing equipment, we need to provide for the presence of an ADSL modem in its composition.
For wireless devices, you need at least two Wi-Fi access points (2 floors). The task is facilitated by the fact that the number of NET sockets on each floor does not exceed three. This allows you to minimize the number of equipment necessary to build a local network.
A homemade LAN network for a two-storey house of 200m2 can be performed on an ADSL router and an Ethernet switcher.
The network structural scheme is shown on fig.2.

Fig.2.

The main characteristics of the applied devices:

D-Link DSL-6740U

Device Type: DSL Modem, Router, Wi-Fi Access Point
Support: VDSL2, ADSL2
Wireless standard: 802.11b / g / n, frequency 2.4 GHz
Max. Wireless speed: up to 300 Mbps (802.11n)
WPA / WPA2 encryption technology
Switch: 4xLan.
Port speed: 100 Mbps
Sizes (shXGHV): 228x175x40 mm
Weight: 460 g
Completeness: router, power adapter, RJ-45 cable, RJ-11 cable, splitter, disk with software.

D-Link DIR-615 / K1A

Device Type: Wi-Fi Access Point, Switch
Max. Wireless Speed, Mbps - 300
Wireless standard: 802.11n, frequency 2.4 GHz
Data Encryption: WPA, WPA2
Number of Ethernet ports - 4
Port speed: 100 Mbps
Sizes (HCHX): 117x193x31 mm
Weight: 940 g
Completeness: router, network adapter, cable RJ-45, 2 external antennas, disk with software.

Network scheme

Mounting (weak) wardrobe It is best to post in such a place, much more convenient to bring cables from all rooms and provides a reliable Wi-Fi access point coverage. In this project - in the hall of the first floor. There will also need to hold a cable from the provider.
The second mounting cabinet is installed in the lobby of the second floor. In the mounting cabinets also provide electrical outlets for powering routers.

From low-current cabinet "Star-like" diverges cables separately for an Ethernet network, telephone and television. At the ends of these cables, separate sockets are installed for each system: telephone and computer (symmetrical) and television (coaxial). The living room has a dual socket (telephone + computer).

Thus in the building, three cable systems are formed in the building and three types of outlets. Such a scheme is more reliable and convenient for installation - each cable system can be mounted almost independently.
The layout of telephone, television and Ethernet networks is shown on fig.3.

Fig. 3.

Installation of equipment

Installing and connecting routers Does not cause any difficulties. The main thing is to determine the place in the mounting cabinet, where it will be located, and it is good to fix it. For mounting in a vertical position in the bottom of the router there are special curly grooves for which it hangs and fixes in the closet or on the wall. Some models are equipped with special stands or panels for vertical location.

If the article you liked and you appreciate the efforts invested in this project – you have the opportunity to make a cash contribution to the development of the site on the page. "Project Support." "Electrician for home". It is dedicated to the basics of electrical engineering and electricity with an emphasis on home electrical installations and processes occurring in them.

Vector 2D CADE editor for Windows developed by a company specializing in working with CAD. The program allows you to easily compile a detailed network scheme. One of the most useful, in my opinion, functions - the ability to sign the IP address, serial number and the name of the manufacturer for each device on the network. Cade includes all the templates needed to draw up and distributes absolutely free.

Concept Draw Pro is one of the most powerful business tools for drawing diagrams, not only network. The development of the program requires a minimum of time - all operations are carried out by simple dragging. The Concept Draw Pro includes a complete set of network symbols, and all aspects of the chart can be personalized. The cost of the application is 249 dollars.

DIA - open software for drawing up diagrams, the main disadvantage of which is an outdated interface and a primitive character set. But the program is very easy to use, without distracting any foreign tasks. DIA is distributed free and works in almost all Linux desktop distributions.

Diagram Designer - another free utility with an outdated interface, but very simple in circulation, so many users will probably have to taste. Unlike the DIA, the program offers a much wider selection of characters and icons. The only thing I did not like in the Diagram Designer is the need to draw connections between computers manually, because for this, an arbitrary form is used in the program. With the exception of this little disadvantage, DD is a completely decent decision.

eDRAW MAX is one of the best tools in this list, except, of course, Visio. The program is easy to learn, has convenient, and more than the most modern user interface from all listed options. EDRAW MAX is a political means for making business diagrams of any destination, and not just network schemes. The cost of the solution is $ 99.95 per license, and the more licenses, the cheaper each of them is.

There are uncomfortable programs, and Govisual Diagram Editor is one of them. This is a complex tool in circulation, providing far from satisfactory results. Although it is still possible to make a network scheme, it will not be particularly easy to read, because in Govisual Diagram Editor there are no some useful functions - in particular, network devices icons. But if someone needs a free program to compile diagrams of any destination, Govisual is just a suitable option, because it spreads out in vain.

Lanflow I would include the best. The program has an excellent interface, offers a rich selection of network objects and allows you to easily create schemes for the local, telecommunications, external network, as well as computer diagrams. In Lanflow, even two different network diagrams template are provided: 3D diagram and black and white. To create a scheme, it is enough to choose a template and drag the suitable objects that can be grouped, deleted and so on. A single-user license for a program costs $ 89, so that Lanflow can rightfully be called one of the best budget alternatives to Visio.

Although NetProbe can also be used to drafting, the main purpose of the program is monitored by real-time network devices. But the main advantage of NetProbe as a means for constructing diagrams is that network devices can be added to the scheme as needed, even in advance. Do this manually do not necessarily - the built-in NetProbe component automatically scans the network and makes up a list of all devices available on the network. Standard is free, but can track only eight hosts. PRO version is only $ 40 and is designed for 20 hosts, and the Enterprise version allows you to monitor 400 hosts, is offered at a price of $ 295.

Network Notepad (Literally "Network Notepad") is exactly what follows from the name - notepad to compile network diagrams. But despite the seeming simplicity, the program has rich capabilities, including interactive functions (Telnet, network viewing, pinging, etc.). NETWORK NOTEPAD has a simple interface with dragging support and can automatically detect Cisco devices. The program is distributed free of charge.

Visio is, of course, the actual standard on the application market for drawing diagrams in Windows. The program allows you to easily create beautiful network schemes and provide access to them through a web browser. Visio includes a rich set of templates, including for data centers, help services, network racks; for office consolidation, network planning across enterprise, data center or home office; To compile a tree of faults, heating, ventilation, ventilation, air conditioning plan, etc. Visio is the best solution for making network schemes, and therefore it is expensive: $ 249.99 for the version of Standard, 559.99 for Professional and 999.99 for Premium 2010. Learn more about version features can be found on the official Visio page.

Materials