What are LAN and SCS? What's the difference? Structured cabling system (SCS) - what is it

SCS- structured cabling network. Or, roughly speaking, “sockets in the wall.” The most expensive thing in SCS is not the sockets, but the huge kilometers of wires connecting the sockets to the server and switching ones.

The layer of concepts that are hidden behind the SCS is very extensive. They have their own professionals who know when to organize switching rooms on floors, how to properly route a bundle of fibers between floors, etc. There are also marketers whose task is to convince you that you need to do it exactly this way, $Xk more in the estimate, and not the way you wanted.

The field of SCS design itself is closer to construction (engineering) work than to the field of system administration.

But sometimes in the life of a system administrator a situation arises when it depends on him what kind of SCS will be in the building (floor, room) of the company. In the worst case, the system administrator carries it out himself, in the best case, this task is outsourced (more precisely, to contractors). But what SCS will be is usually decided by two or three people. At the same time, the remaining two determine only the budget, and only a system administrator can fight for quality. [on the other side there is a representative of the contractor, who is dragging the blanket in his direction, and although he may seem like a comrade-in-arms to the system administrator in the battle for the quality of SCS, in fact, he just wants more money, and should be treated with caution].

Here I am writing precisely from the point of view of the administrator, as the “end user” of the SCS. If I lied somewhere, or forgot to write about something important, tell me, I’ll correct you.

So, SKS.

Owner's (director's) point of view

You need wires with sockets. The cheaper the better. The administrator once said that computer computers can be branched locally, so you can put them in smaller quantities, because they are expensive. By the way, there are a bunch of people sitting there, one socket is enough for them.

Contractor's point of view

The client needs to sell the maximum. At most, this is a full-fledged SCS with switching rooms on the floors, interfloor optics... What? Does he want something cheaper? Well, to hell with him, let him do what he wants.

What do YOU need from SCS?

Speed

Write down for yourself the minimum you need. Despite the stories of marketers, most modern applications 10 megabits is enough for the eyes and ears. Rare application 100 megabits are needed (mainly due to pumping a large amount of data). If the application needs gigabit, then perhaps you have made a mistake with the installation location (maybe it’s better to be closer to the servers?). Write down everything that is usually done on the computer. It turns out that most of these tasks are not at all demanding on speed. If you haven’t found such applications, then the technical specification clearly states a requirement of category 5e, and not 6, as they may try to persuade you to do.

Telephony

Some companies use IP phones and are not interested in this issue. If your IP ends near the PBX or you are using old telephony, then telephone sockets are needed. The question is how to make them?

Options:

On the same wire with ethernet
Several telephone pairs in one wire
Separately, a separate wire for each socket.

The first option (ethernet + phone), formally, is acceptable (there can be two applications in one cable), but in my practice I have encountered a cable in which packets began to be lost at the moment the call went through. The main advantage of this solution is saving on wires. The main disadvantage is the need to separate it all. It's inconvenient.

The second option (ethernet separately, telephony 4 pairs per wire) is a little better, but is complicated by the problem of wiring in the wall from socket to socket. If your contractor is ready to do this without additional charges. payment - this may be an option. The downside is that SCS is not universal (more on this below), the upside is significant savings on cables (1 cable instead of 4).

The third option (each outlet has a separate cable) is the most interesting and most expensive. You have a strict set of wires between the server (switching) and the socket. What to use through it (ethernet or telephony) - you decide. The peak of versatility is the RJ45 sockets for both ethernet and telephony (RJ11 telephone sockets are included in RJ45).

The third option is very important in terms of versatility. Need two phones? (fax + telephone) - please, here are two sockets, you can use them. Do you need another print server instead of a phone? Please.

This option is the easiest to switch (1 wire - 1 application), the most easily debugged and reliable. And the most expensive.

If you have a large building, then with 500 telephone sockets you will lose about 12 kilometers of cable (you can calculate the price yourself) compared to the first option and about 18 kilometers of cable compared to the second.

How many sockets

The main stumbling block. Every outlet is MONEY. Every socket not used is money down the drain. Usually the directorate looks at the employee seating plan, determines the number of sockets, allows, well, a maximum of +2 in reserve - and that’s it. And then it turns out that in a room for 10 people there are only 3 pairs of sockets. Because previously it was thought that this would be a presentation room, but now it is an accountants’ room. Oh, yes, we need two more network printers, one for that wall and one for this one. No outlets? Who cares?

The solution to the problem is to place sockets not according to the number of employees, but according to the MAXIMUM POSSIBLE number of workplaces. Those. according to the footage of the room.

It turns out to be EXPENSIVE. About 1.5-4 times more expensive than if done “for working people.” But at the same time, SCS becomes universal, i.e. Suitable for any number of employees in any location.

Argument for management: if we make SCS based on the number of jobs, then when we change the business profile or transfer employees, all the money will go down the drain, we will have to redo it. If you make SCS by footage, then SCS will not be an attribute of the current state of affairs in the company, but an element of the premises (building); it becomes a capital investment in real estate, increasing its market value and versatility of application.

Switching

(this applies to the case when SCS is on several floors).

We can drag all the wires to the server room. There will be a LOT of them. In one of the organizations where I worked, this tourniquet could barely be grasped, almost a meter in diameter. The advantage of this is the very versatility - the wires run in a straight line (in the sense, without breaking the electrical connection), you can plug anything into them - from a telephone to a video camera.

Or maybe we can do something more cunning. We lay the vertical part of the SCS (interfloor connections), and on each floor we select a nook into which the wires from the floors converge. In principle, there can be even more than one such nook on a floor.

SCS on the floor is universal. Interfloor SCS - specialized.

Interfloor SCS: between floors there is a gigabit, or even all ten, or even optics, or even... (let’s not forget about modesty in this place, and stop at gigabit), a switch is installed. Telephony is carried out in a multi-multi-multi-pair cable, which is routed to patch panels or cross-connects (kron66 or something similar). Next, the universal SCS of the floor is switched as desired between the options “telephony”, “ethernet”, “alarm”, etc.

The advantage of this solution is that several thick telephony wires converge into the server room (which are installed in the PBX and you don’t have to think about them anymore), several gigabit (10 gigabit) cables that connect to switches (apparently to the distribution level, if you follow the Cisco circuit diagram). The server room is free of wires, everything “low-lying” for the user is removed from the server room. There is no need for non-essential personnel to look there to run wires for the transferred employee, only everything that is Very Important remains there.

However, from these advantages come disadvantages. Removing part of the equipment from the server room to the switching room (it is clear that in a good way this should be a small room, in reality it is usually a switching box under the ceiling, or even on the floor in one of the offices) leads to an increase in the vulnerability of the SCS. Dust, dirt - that's the first thing. Second - unauthorized access(you give a person the opportunity to carry out an ideal man-in-middle attack in a remote corner of the building) and hooliganism. Third, SCS is losing its versatility. What if there weren’t enough telephone pairs for the floor? And on the floor below, 10 pairs out of 200 are used...

aggressive branching

(I don't know what this scheme is called officially)

Instead of a single switchboard, we make many shelves. Relatively speaking, for every 1-2 rooms there is a separate switching shelf. It comes with 1 ethernet and 1 paired telephone cable. This scheme is intermediate. On the one hand, you have fewer wires from the server room (not in terms of the number of workstations, but in terms of the number of cabinets), on the other hand, the SCS of a separate room can be redone with little effort. These are the advantages.

Cons - the same problem of unbalanced applications (if there is not enough telephony in the room, what do we do?), many places where shelves are located (these places are not always obvious and well documented, I once found such a switching room in the middle of the room above a false ceiling) . Placing electrical equipment (switches) requires power supply (can be partially mitigated by PoE, but it's expensive...).

This solution has the most cheap option"is a hub (switch) under your feet or in a corner. Several wires come out of the server room to the switches, from these switches there are wires to neighboring switches... So you can provide a couple of hundred sockets at the cost of 3-4 bays (300m*4=1.2km) of wires, several desktop switches and patchcords, which are usually not patchcords but the same twisted pair, but compressed. [Reference: monolithic twisted pair (in which each wire is solid copper) has best characteristics, but low mechanical strength, “real” patch cords have multi-core fibers, which are worse for data transmission, but are better able to withstand bending, stepping on, and being pinched by chairs and tables]. It is this option that you should run away from like hell, because it will cause so many problems that words cannot describe it (switches will lose power, freeze, cables will get tangled and dirty... I don’t even want to think about this).

Switchboards and shelves

The most radical option: a vertical cable network comes to the floor, a horizontal cable network goes from the floor, to the shelves in the rooms, from the shelves in the rooms there is an “in-room SCS” to the sockets at the workplaces.

Pros are the sum of the previous pros.

The disadvantages are the same, but another one appears: the more switching occurs with the application, the worse signal(we're not talking about switches, of course, although they also increase latency, which can be unpleasant in some applications). 8 connectors from the phone to the PBX is quite a worthy reason to start wheezing into the handset in a year or two.

An interesting feature of this solution is that it fits perfectly into the core-distribution-access model. At the same time, the most important wires - interfloor ones, usually run in a box, there are few of them there (this is important, because a small box is easier to make), they are well protected (possibly inside the walls).

What for are all these wires?

And here another interesting scheme is drawn, this is wifi and dect. If instead of SCS by room you place it indoors wifi points access and dect" phone bases, the number of wires will be significantly reduced.

However, this still will not solve the problem of bringing the wire to the floor (room), and the quality/speed of wifi is not comparable to good ethernet (both in terms of delay and the probability of packet loss).

What to choose?

Back to the first punts again. First you must decide how the outlets will be distributed. By people, or by square meters.

Next, you need to calculate how many wires there will be. If it’s less than a couple of hundred (and if the length of the wires falls within the 100m limit), there’s no point in bothering with switching cables. If there are a lot of wires or long distances, you should think about switching wires. If there is even the slightest opportunity to win back the premises, and not the closets, we need to fight for the premises. No windows, no radiators, no walk-through doors. Just a storage room.

Which wire to choose? In fact, any, the cheapest, for which the contractor is ready to vouch for the quality. The cheapest certified wires (able to pass certification) perform as well as oxygen-free copper twisted pair silver cable with a ferrite piercing.

But with sockets and patch panels everything is much worse. Bad sockets are an eternal torment for the administrator.

So which outlet is good?

The core should hold up well. If it's on screws, great. Auto-latching ones often break and then dangle like worms inside the box.
A downward tilt or a lid is a small plus (less dust)
The twisted pair cable should be crimped using a hammer, not a plastic cap with teeth. These teeth compress the pair worse than the striker.
Durable (sorry for the banality): it should hold the wire normally and not creak when moving the wire inside the socket. It has been working for years, and no one promises that the wires will be turned on/off carefully.

Telephony patch panels are a place for holivars. To begin with: should telephony be installed on patch panels or on crowns? If it’s on a crown, it’s compact, very compact. If it is on a patch panel, switching can be done without a striker or force.

There are similar holiwars around patch panels for ethernet. Are they needed or not? After all, wires can come “directly” and be plugged into switches. At the same time, there are fewer mechanical contacts and unraveling, i.e. the path turns out to be more reliable. From the side of supporters: patch panels allow you to organize your household Right. As experience shows, if there are a lot of free units, then patch panels are installed. If there are few units, then they usually skimp.

Which option to choose is up to you.

Numbering

Minus the wires, the second (and maybe even the first) value of the SCS is its circuit. The diagram should show which outlet goes where and HOW it goes (i.e., the locations of the wires should be clearly marked on the building plan). Even more important is the presence of socket numbers, both on the sockets themselves and on the “server” side (i.e., on the side that is routed to the patch panel or switchboard). If there are no numbers, you can throw away the SCS (or start a long, painful numbering procedure). The numbers should be written in such a way that they are easy to read (ie handwritten numbers are not so much) and in such a way that they will remain for years. Those. pencil is definitely a no.

Is it necessary to number patch cords between patch panels and equipment during switching? I used to think so. Now I doubt it, because in a proper SCS these wires are obviously visible and easy to find.

Patch cords

Well, one last thing. Patch cords MUST have a cap, a cap, a reverse tab... Anything that will protect the jack latch from catching on the wires when pulling the wire through neighbors. THIS IS IMPORTANT. Believe me, I have personally struggled with 400+ wires WITHOUT caps. This is HELL. Instead of a simple “pull and pull”, you have to manually untangle each wire from its neighbors; the untangling process splits the neatly laid wires and prevents you from pulling out other wires... A cap (or at least a plug on the back) is a MUST.

Add-ons

Thanks to those commenting. Moments that were not described.

Switching log. I don’t know how “good” it looks in theory, in my work it looked like a spreadsheet file that contained a list of sockets and an indication of “to whom” this or that socket is assigned. There was an attempt to number patch cords, but it gradually died out due to general laziness. Apparently, in theory, for each switching room there should be a magazine in which it is written “such-and-such socket - such-and-such socket” (port of such-and-such device).
If patch cords have already been purchased without caps, electrical tape is an emergency solution. Although it gets dirty and gets in the way. Caps are better
It is good to have organizers under the patch panels. Invaluable units are wasted on this, however, the SCS gains accuracy and completeness.
If you give the SCS to the contractor, do not skimp on paying for the preparation of the technical specifications. They (contractors) will compose it more intelligently. Coordinate their (reasonable) project, making adjustments and explaining what you want better than... um... inventing your technical specifications
Standards for further googling: EN 50173, ISO/IEC 11801
For those who want to look at beautiful racks with beautifully laid wires:

The structured cabling system (SCS) is the fundamental basis throughout the entire existence of the information network. This is the basis on which the functioning of all applications depends (Fig. 81). A properly designed, installed and managed cabling system reduces costs for any organization at all phases of its life.

Rice. 81. Comparative indicators of the average lifetime of elements of a distributed information processing system

According to statistics, imperfect cable systems are the cause of up to 70% of all information network downtime. Although cable systems tend to last longer than most network components, its cost is only 5% of the total investment in information network. Thus, using structured cabling systems is a very compelling way to invest in the productivity of any organization or company.

The cabling system is the longest-lived network component, outlasting only the building frame. A standards-based cabling system ensures long-term network performance and support for all numerical applications, providing a return on investment throughout its lifespan.

Hierarchy in the cable system

A structured cabling system (SCS) is a set of switching elements (cables, connectors, connectors, cross-connect panels and cabinets), as well as a technique for using them together, which allows you to create regular, easily expandable connection structures in computer networks.

A structured cabling system is a kind of “constructor” with the help of which the network designer builds the configuration he needs from standard cables connected by standard connectors and switched on standard cross-connect panels. If necessary, the connection configuration can be easily changed - add a computer, segment, switch, remove unnecessary equipment, and also change connections between computers and hubs.

When building a structured cabling system, it is assumed that each workplace in the enterprise must be equipped with sockets for connecting a telephone and computer, even if this is not currently required. That is, a good structured cabling system is built redundant. This can save money in the future, since changes in the connection of new devices can be made by reconnecting already laid cables.

A structured cabling system is planned and built hierarchically, with a main trunk and numerous branches from it (Fig. 82).

Rice. 82. Hierarchy of a structured cabling system

This system can be built on the basis of existing modern telephone cable systems, in which cables, which are a set of twisted pairs, are laid in each building, routed between floors, on each floor a special cross-connect cabinet is used, from which wires in pipes and ducts are brought to each room and are provided with sockets. Unfortunately, in our country, not even all newly built buildings have telephone lines laid with twisted pairs, so they are unsuitable for creating computer networks, and in this case the cable system must be built anew.

A typical hierarchical structure of a structured cabling system (Figure 83) includes:

horizontal subsystems (within a floor);

vertical subsystems (inside the building);

campus subsystem (within one territory with several buildings).

Rice. 83. Structure of cable subsystems

The horizontal subsystem connects the floor's cross-connect cabinet to the users' sockets. Subsystems of this type correspond to the floors of the building. The vertical subsystem connects the cross-connect cabinets of each floor with the central equipment room of the building. The next step in the hierarchy is the campus subsystem, which connects several buildings to the main control room of the entire campus. This part of the cabling system is usually called the backbone.

Using a structured cabling system instead of haphazardly routed cables provides many benefits to a business.

Versatility. A structured cabling system, with thoughtful organization, can become a single environment for transmitting computer data on a local computer network, organizing a local telephone network, transmitting video information, and even transmitting signals from fire safety sensors or security systems. This allows you to automate many processes of control, monitoring and management of economic services and life support systems of the enterprise.

Increased service life. The obsolescence of a well-structured cabling system can be 15 years.

Reduce the cost of adding new users and changing their placements. It is known that the cost of a cable system is significant and is determined mainly not by the cost of the cable, but by the cost of laying it. Therefore, it is more profitable to carry out a one-time job of laying the cable, perhaps with a larger margin in length, than to carry out the laying several times, increasing the length of the cable. With this approach, all work on adding or moving a user is reduced to connecting the computer to an existing outlet.

Possibility of easy network expansion. The structured cabling system is modular and therefore easy to expand. For example, you can add a new subnet to a backbone without having any impact on existing subnets. You can change the cable type on a specific subnet independently of the rest of the network. Structured cabling is the basis for dividing the network into easily manageable logical segments, since it itself is already divided into physical segments.

Providing more efficient service. A structured cabling system makes maintenance and troubleshooting easier than a bus cabling system. With a bus-based cable system, the failure of one of the devices or connecting elements leads to a difficult-to-localize failure of the entire network. In structured cabling systems, the failure of one segment does not affect the others, since the segments are combined using hubs. Concentrators diagnose and localize the faulty area.

Reliability. A structured cabling system has increased reliability because the manufacturer of such a system guarantees not only the quality of its individual components, but also their compatibility.

The first structured cabling system to have all the modern features of this type of system was the SYSTIMAX SCS system from Lucent Technologies (formerly a division of AT&T). And today Lucent Technologies owns the major share of the global market. Many other companies also produce high-quality structured cabling systems, such as AMP, BICC Brand-Rex, Siemens, Alcatel, MOD-TAP.

SCS (structured cabling systems)

Installation of trays and laying of structured cable networks

Structured cabling systems greatly simplify and optimize the management of various cabling systems. Installation of SCS allows you to combine into a single information space systems such as: security – fire alarm, access control control, video surveillance, telephony, LAN - local area networks (Internet), devices, control panels, control panels, distribution devices and other related equipment. Laying such networks in large enterprises can be especially difficult due to its volume, and even a small failure of one node can lead to the shutdown of the entire SCS. This is complex, responsible work, and for such a system to be reliable, the installer is required not only to carefully read the design documentation and practical skills, but also a clear knowledge of SNIP and, of course, extensive experience. Therefore, a guarantee for long and uninterrupted operation is provided by the installation of qualified specialists working in our company.

Low-current cables mounted in a mesh tray

List of works when creating SCS:

Installation of mini cable channel;
Installation of end caps;
Installation of passage holes - channels into the monitor room, followed by
Laying vertical and horizontal lines in the monitor room;
Accurate and high-quality testing of SCS network lines;

Now let's talk about those very systems that can be grouped into a single SCS information space.

LAN - Local Area Networks

Local area networks (LAN) serve as the basis for building information structure in industry, science, education, services, management cellular communications, small, medium, not to mention large businesses and other areas of human activity. The creation of a LAN is a key condition for the functioning of any company and is one of the most important systems for the organization full-fledged work office. Routers, flash cards, printers, copiers are all part of digital technologies that indirectly or directly interact with a pre-provided Internet connection. Let's consider the need for a LAN using the example of a small business. Let's imagine an office of an organization consisting of four to five rooms and having up to ten employees on staff. For such a team to work successfully and without conflict, computers connected to a local area network must be installed at all workplaces. But this is not enough. For example, to build a LAN in the Small Business Development Bank for 692 workplaces, directly in which installation was carried out by our specialists, in addition to compliance with all standards and SNIPs, it is necessary to take into account factors including the maximum permissible segments of operation of network equipment, the maximum cable length of one segment, the maximum permissible number of computers connected to one segment and, of course, a server that accumulates, processes and stores information from all participants in the work process. LANs are not intended for high loads on the network and has several structural types:

Ring. This type of structure includes network elements united among themselves by closed circuit sequentially	Star. This type of structure involves connecting all component systems to a single central node
Tire. When using this type of structure, all information is transferred over communication channel and is equally available for all devices	Tree structure. This type is a combination basic structures and is used in large networks with assignment of the highest LAN level

Important issues that you need to pay attention to when creating a LAN:

Placement of the workplaces themselves;
Installation of equipment;
Carefully consider where the server will be installed;
Mounting height of the box and sockets.

Key benefits locally computer networks:

Opportunity quick access to the necessary information;
Sharing network resources (scanners, printers, modems);
Use of modern technology resources;
Electronic document circulation systems;
Protection of information from hacking;
Reliable data storage;
Fax transmission, network databases;
Uninterrupted Internet access.

List of works when creating a LAN:

Drilling through holes in walls and ceilings;
Ceiling installation of electrical trays for UTP cables;
Installation of electrical trays under the raised floor with subsequent laying of UTP cable;
Installation of mini cable channel;
Installation of plastic legrand boxes;
Installation of dividing partitions in legrand boxes;
Installation of frames in legrand boxes for Internet sockets;
Crimping RJ45 computer chips;
Installation of internal corners in a legrand box;
Installation of external corners in the box;
Installation of flat corners in the box;
Installation of outlet tees when installing legrand boxes;
Installation of end caps;
Installation of passage holes - channels into the server room, followed by
laying sleeves under cable routes;
Laying vertical and horizontal lines in the server room;
Accurate and high-quality testing of LAN network lines;

Compliance of a LAN with ideal requirements is, first of all, the physical accessibility of cable routes for changing the configuration of local computer networks, where it is possible to connect additional equipment without changing the technical and software parameters of the network itself. Secondly, do not forget about such a concept as network flexibility. If a particular computer or any other equipment malfunctions, the network continues to function!

The field of SCS design itself is closer to construction (engineering) work than to the field of system administration.

So, SKS.

Owner's (director's) point of view

Contractor's point of view

What do YOU need from SCS?

Speed

Write down for yourself the minimum you need. Despite the stories of marketers, 10 megabits is enough for most modern applications. A rare application needs 100 megabits (mainly due to pumping a large amount of data). If the application needs gigabit, then perhaps you have made a mistake with the installation location (maybe it’s better to be closer to the servers?). Write down everything that is usually done on the computer. It turns out that most of these tasks are not at all demanding on speed. If you haven’t found such applications, then the technical specification clearly states a requirement of category 5e, and not 6, as they may try to persuade you to do.

Telephony

Some companies use IP phones and are not interested in this issue. If your IP ends near the PBX or you are using old telephony, then telephone sockets are needed. The question is how to make them?

Options:

On the same wire with ethernet
Several telephone pairs in one wire
Separately, a separate wire for each socket.

This option is the easiest to switch (1 wire - 1 application), the most easily debugged and reliable. And the most expensive.

How many sockets

The solution to the problem is to place sockets not according to the number of employees, but according to the MAXIMUM POSSIBLE number of workplaces. Those. according to the footage of the room.

Switching

(this applies to the case when SCS is on several floors).

SCS on the floor is universal. Interfloor SCS - specialized.

However, from these advantages come disadvantages. Removing part of the equipment from the server room to the switching room (it is clear that in a good way this should be a small room, in reality it is usually a switching box under the ceiling, or even on the floor in one of the offices) leads to an increase in the vulnerability of the SCS. Dust, dirt - that's the first thing. The second is unauthorized access (you give a person the opportunity to carry out a perfect man-in-middle attack in a remote corner of the building) and hooliganism. Third, SCS is losing its versatility. What if there weren’t enough telephone pairs for the floor? And on the floor below, 10 pairs out of 200 are used...

aggressive branching

(I don't know what this scheme is called officially)

This solution has the “cheapest option” - a hub (switch) under your feet or in a corner. Several wires come out of the server room to the switches, from these switches there are wires to neighboring switches... So you can provide a couple of hundred sockets at the cost of 3-4 bays (300m*4=1.2km) of wires, several desktop switches and patchcords, which are usually not patchcords but that Same as twisted pair, but crimped. [Reference: monolithic twisted pair (in which each wire is solid copper) has better characteristics, but low mechanical strength, “real” patch cords have multi-core fibers, which are worse for data transmission, but are better able to withstand bending, stepping on, being pinched by chairs and tables]. It is this option that you should run away from like hell, because it will cause so many problems that words cannot describe it (switches will lose power, freeze, cables will get tangled and dirty... I don’t even want to think about this).

Switchboards and shelves

Pros are the sum of the previous pros.

The disadvantages are the same, but another one appears: the more switching occurs with the application, the worse the signal (we are not talking about switches, of course, although they also increase the latency, which can be unpleasant in some applications). 8 connectors from the phone to the PBX is quite a worthy reason to start wheezing into the handset in a year or two.

What for are all these wires?

And here another interesting scheme is drawn, this is wifi and dect. If, instead of SCS, wifi access points and dect telephone bases are placed indoors in rooms, then the number of wires will be significantly reduced.

What to choose?

Back to the first punts again. First you must decide how the outlets will be distributed. By people, or by square meters.

But with sockets and patch panels everything is much worse. Bad sockets are an eternal torment for the administrator.

So which outlet is good?

The core should hold up well. If it's on screws, great. Auto-latching ones often break and then dangle like worms inside the box.
A downward tilt or a lid is a small plus (less dust)
The twisted pair cable should be crimped using a hammer, not a plastic cap with teeth. These teeth compress the pair worse than the striker.
Durable (sorry for the banality): it should hold the wire normally and not creak when moving the wire inside the socket. It has been working for years, and no one promises that the wires will be turned on/off carefully.

Which option to choose is up to you.

Numbering

Patch cords

Add-ons

Thanks to those commenting. Moments that were not described.

Switching log. I don’t know how “good” it looks in theory, in my work it looked like a spreadsheet file that contained a list of sockets and an indication of “to whom” this or that socket is assigned. There was an attempt to number patch cords, but it gradually died out due to general laziness. Apparently, in theory, for each switching room there should be a magazine in which it is written “such-and-such socket - such-and-such socket” (port of such-and-such device).
If patch cords have already been purchased without caps, electrical tape is an emergency solution. Although it gets dirty and gets in the way. Caps are better
It is good to have organizers under the patch panels. Invaluable units are wasted on this, however, the SCS gains accuracy and completeness.
If you give the SCS to the contractor, do not skimp on paying for the preparation of the technical specifications. They (contractors) will compose it more intelligently. Coordinate their (reasonable) project, making adjustments and explaining what you want better than... um... inventing your technical specifications
Standards for further googling: EN 50173, ISO/IEC 11801
For those who want to look at beautiful racks with beautifully laid wires:

SCS stands for "Structured Cabling System". This is such a broad concept that sometimes SCS is understood only computer network either only power or only. But SCS is “more than that”. The cable system may include several types of cable systems:

Computer network. Cables and equipment needed to operate computers on a network.
Telephone network . All telephony of the company, including office Mini PBX, as well as telephones.
Power systems. - these are not only low-current networks. Power wiring systems can also be classified as SCS systems.
Fire protection and burglar alarm . Being low-current, these systems also belong to SCS systems.
Video surveillance and access control systems. Also refers to SCS systems.
Administration of SCS. It is important to emphasize that SCS is not only wires. SCS also includes all project documentation, regulations, access rights, as well as all regulatory and administrative procedures, without which the operation of a structured cabling system is impossible.

independent of the terminal equipment, it connects various data exchange points: computers, sensors, power sources and consumers, various digital and analog devices, such as video cameras, magnetic card readers, etc. is a set of passive communication equipment, which includes:

Cables. A cable is a medium for transmitting data or signals. Typically copper cable or fiber optics are used.
Sockets. The socket is a terminal passive equipment. It is designed for switching terminal equipment using patch cords.
Patch panels. And patch cords. The structure of the SCS is always distributed, i.e. terminal equipment is distributed throughout the knowledge or room. Patch panels provide connectivity (switching) in the right way cable lines. A patch cord is a piece of cable with two connectors at the ends. Used to connect terminal equipment to SCS.
Wiring cabinets and racks. If the number of sockets is tens or hundreds, then all switching equipment is placed in special switching cabinets or racks. Cabinets and racks, in turn, are located in the server room or in a specially designated room. As a rule, everyone is brought into the server (switching) room cable lines.

Requirements for SCS

The structure of the cable system must meet the specified requirements. Despite the constant development of technology and the emergence of more and more new devices, the basic requirements for SCS remain unchanged:

The SCS must provide transmission of various types of signals, be it computer digital or analog video data.
The SCS must ensure the operation of all generations of networks and devices used, i.e. be integrated. For example, with the advent of optical fiber, media converters appeared that made it possible to connect a copper pair and an optical cable.
The SCS must provide the required speed of data and signal transmission. The speed of the main SCS channel can differ significantly from the data exchange speed of one computer or workstation.
The SCS must have central administration. Typically, the network structure is built on the “star” principle, in which the central node performs administration functions, while itself being part of more high level. That. SCS administration is not only centralized, but also hierarchical.
The SCS must be independent of data transmission protocols and, in general, ensure the use of several protocols. The communication protocol is usually determined by the terminal equipment.
SCS should strive to reduce maintenance and modernization costs. Competition in the market and technology development make it possible, under all equal conditions, to choose the supplier with the most favorable price. The quality of SCS work does not deteriorate. This requirement is realized largely due to standardization.
Terminal equipment can be moved without changing its settings. Users can connect to SCS in different points. This does not change their credentials.
Administration transparency. The SCS must be accompanied by documentation, have the necessary markings and not depend on specific employees.
SCS must have a performance reserve. This requirement may seem strange, but it makes it possible for many years to forget about the need to constantly increase the power of computer and other systems. Typically, from 10% to 40% of the reserve is laid down. This reserve can be expressed in the number of reserved ports, sockets, as well as in the performance of network equipment. The typical service life of SCS is from 10 to 40 years.

SCS standards

Standardization of SCS covers all stages of its construction and subsequent use. The standards define the structure of the SCS, the operating parameters of the passive and active equipment, design rules, rules for drawing up design documentation and much more.

There is no single, global SCS standard. There are a number of international and local standards, such as American, European, Canadian, etc. First of all, SCS standards are addressed to installers and builders, because Compliance with all standards is especially important at the construction stage of SCS.

In Russia, as a rule, the ISO/IEC 11801 standard is used because Russia is a member of the International Organization for Standardization ISO.

According to the ISO/IEC 11801 standard, a structured cabling system is divided into three parts:

Horizontal subsystem.
Trunk subsystem of the building.
Trunk subsystem of a building complex.

The backbone subsystem of buildings is also sometimes called the vertical subsystem of SCS, because it basically connects the floors of the building and has a vertical direction.

1 - Workplace.
2 - Horizontal subsystem of SCS.
3 - Floor switching unit.
4 - Vertical subsystem of SCS.
5 - Service technical means.

Horizontal subsystem SCS

As a rule, the horizontal SCS subsystem connects the workplace with the floor distribution unit. In some cases, a horizontal subsystem may combine several or all floors of a building. The horizontal subsystem is usually implemented using UTP or STP cable of category 5e or higher. The copper pair has a length limit of 100 meters, so for longer rooms the installation of intermediate active equipment is required. More than 90% of the cable falls on the horizontal SCS subsystem. The cables themselves are laid in several ways:

Hidden cable routing in the wall, under the ceiling or in a false floor. Hidden cable wiring provides for the installation of built-in sockets and installation of floor hatches.
Laying the cable in the cable channel. Typically, PVC plastic boxes from various manufacturers are used.
Laying in cable trays and using hangers.

A workstation or work area includes all user terminal devices. The workplace is usually equipped with two information sockets into which the completed equipment is connected using a patch cord. Patch cords are usually 1.5-5 m long and have a standard RJ-45 connector.

The floor switching center is the place where all horizontal cables are switched. The switching unit is made either in the form of a rack or in the form of an installation cabinet. If necessary, a special room is allocated for the communication center.

Vertical subsystem of SCS

The vertical subsystem of the SCS connects the distribution cabinets of the floors. It is part of the horizontal SCS, but has a vertical direction. The vertical subsystem is characterized by the use of high-speed communication channels, such as gigabit ethernet or optical fiber.

All vertical communication channels converge at a central point (the main switching room), from where they extend outside the building or company. As a rule, a vertical subsystem has several lines, including backup lines, because When a cable breaks or a floor switch fails, an entire floor or more remains unconnected.

The cables of the vertical subsystem of the SCS must meet fire safety requirements.

SCS backbone subsystem

The backbone subsystem connects the cable systems of several buildings. Typically, two types of signals are transmitted over a trunk system: digital and voice.

The most common transmission medium of the backbone subsystem is (single-mode or multi-mode). If the span between switches does not exceed 90-100 meters, copper twisted pair can be used as the transmission medium. On long distances You must use either copper, but only for voice data transmission.

SKS grounding system

All metal elements of the system must be grounded. Particular attention is paid to the connection points of cables coming from different buildings, because they may have different zero potential. In this case, it makes more sense to use fiber optics for the connection.

The main purpose of the grounding system is to protect personnel and equipment from short circuit and from lightning discharges. A grounding point should be available everywhere, especially in server and switch rooms.

SCS power supply system

Digital equipment requires a cleaner diet. Therefore, very often they share a common electrical network and network. At workplaces, in addition to information ones, power sockets necessary for connecting terminal equipment are also installed. Installation of power sockets is also carried out: in a box or hidden in the wall. In special cases, a dedicated phase for powering terminal equipment is reserved using stationary sources uninterruptible power supply. Such solutions are justified for systems that require a guaranteed response (call centers, rescue services, important objects etc.).

Often the power cable is laid in the same box as the information cables. In this case, the transmission quality digital signals may deteriorate due to electromagnetic interference. Therefore, when laying power and information cables in parallel, it is necessary to maintain the minimum permissible distance.

Patch cords or patch cables are an important element of SCS. They connect cable lines located in boxes with terminal equipment. They bear the main mechanical loads, so it is important to monitor proper quality patch cords.

Physically, a patch cord is a piece of cable 1.5 to 5 meters long, which is crimped at both ends with special connectors. Patch cords are not only based on twisted pair, but also fiber optic and telephone patch cords.

Special caps at the ends of the patch cord increase the bending radius of the cable and extend its service life.

Patch panels

Patch panels or patch panels are designed to create a center for switching network information cables. They provide fast re-switching of communication system ports. Physically, the patch panel is a set of connectors on one side and patch combs on the other, rear part. Trunk cables, usually leading to switching or terminal equipment, are connected to the patch panels from the back. Using patch cords, patch panels are connected to active network equipment, providing truly fast and safe reconnection. In fact, every information outlet in the workplace ends in a connector on the patch panel. The connectors are labeled, allowing for quick connection the right socket(according to the marking) with the required port of the active network equipment. Patch panel connectors are usually in RJ-45 format.

The patch panels themselves are mounted in wiring closets, racks or frames. There are wall patch panels.

Information sockets

Information sockets are designed for switching terminal equipment into the network, such as personal computers, network printers etc. Information sockets can be internal (modular) and external. Particularly convenient are modular sockets that are installed in cable channels. This approach allows you to quickly change plug-in modules, expand existing sockets, and replace worn-out ones.

Information sockets usually use RJ-45 connectors into which patch cords are connected.

There are a huge number of cable equipment manufacturers. As a rule, each company presents a complete set of passive cable equipment. The choice of a specific supplier depends on many factors, including the economic features of the equipment.

Wiring cabinets and racks

For the convenience of placing cross-connect and active network equipment, switching cabinets or racks are used. Their peculiarity is that they are standardized and have special guides for attaching equipment. All network equipment the height is a multiple of one unit, which is equal to 44.45 mm. There are usually 40-42 units in a rack. The wiring closet is smaller, usually 6-9 units.

Cabinets and racks have different depths, which must be taken into account when purchasing equipment. In some cases, the depth of the cabinet or wiring rack may not be sufficient.

Typically, cabinets have a locking door, which is very useful if the wiring closet is located outside the server room. The racks also have doors, but they are more of a decorative nature. The posts are often fastened in rows together. In this case, often the racks do not have side walls.

Installation of SCS

Installation of a cable system is an important and responsible stage, as a result of which a structured cable system actually appears. is divided into several stages, such as:

Selecting a standard. It is necessary to immediately decide which standard will be used when installing the SCS.
Preparing the premises. Before installing the SCS, it is necessary to complete the basic construction work, if the building is new. Or prepare the existing premises for construction and installation work on laying SCS.
Installation of cable infrastructure. Trays, cables, racks and wiring cabinets. Installation of passive switching equipment.
Installation of active switching equipment: servers, switches, switches, media converters and other things.
SCS testing and configuration software.
Commissioning of SCS.

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What are LAN and SCS? What's the difference? Structured cabling system (SCS) - what is it

Owner's (director's) point of view

Contractor's point of view

What do YOU ​​need from SCS?

Speed

Telephony

How many sockets

Switching

aggressive branching

Switchboards and shelves

What for are all these wires?

What to choose?

Numbering

Patch cords

Add-ons

Hierarchy in the cable system

Owner's (director's) point of view

Contractor's point of view

What do YOU ​​need from SCS?

Speed

Telephony

How many sockets

Switching

aggressive branching

Switchboards and shelves

What for are all these wires?

What to choose?

Numbering

Patch cords

Add-ons

Requirements for SCS

SCS standards

Horizontal subsystem SCS

Vertical subsystem of SCS

SCS backbone subsystem

SKS grounding system

SCS power supply system

Patch panels

Information sockets

Wiring cabinets and racks

Installation of SCS

What do YOU need from SCS?

What do YOU need from SCS?