Kupfernetze
Basic knowledge of copper networks
Structured cabling
The demand for manufacturer-independent, service-neutral cabling led to the international standard ISO/IEC 11801, on which the German-language DIN EN 50173 is based. It describes structured cabling that should be implemented independently of the current use of the rooms to be wired and independently of any LAN technologies. This standard contains requirements for the individual components and the complete transmission path as well as corresponding test specifications.
Structured cabling is divided into primary, secondary and tertiary cabling. The primary cabling runs between the individual buildings at the same location. With the exception of telephone cables, it consists almost exclusively of fiber optic cables that run from each building to a central site distributor. Secondary cabling refers to the cables between separate data distributors within a building. They run from the individual distributors in a star shape to a building distributor. According to the standard (DIN EN 50173-2:2018), at least one so-called floor distributor should be installed on each floor of an office building, but it is permissible to connect several sparsely populated floors from the distributor of the floor above or below.
The data cables run from the floor distributor to the junction boxes, which is referred to as tertiary cabling. Copper data cables (twisted pair) and connection boxes/distribution panels with RJ45 sockets are mainly used here. Fiber optic cables (FO) to the workplace can be an interesting alternative, depending on the construction project or network size. The telephone network is usually also realized via data lines, only a different pin assignment is required for telephone connections; if all eight wires of a line are laid in the RJ45 socket, it can be used for either telephone or IT.
Telephone and IT distribution via the same network infrastructure is also known as a converged network.
DIN EN 50173
The first version of DIN EN 50173 was published in 1995 and has since been revised and supplemented several times to keep pace with the requirements of constantly increasing data rates.
Currently, components for 10 Gigabit Ethernet up to 500 MHz (Class EA / Category 6A) are used in networks in office buildings, and for 40 Gigabit Ethernet up to 2,000 MHz (Class I / Category 8.1) in data centers
DIN EN 50173 has now become a six-part series of standards, the individual parts of which deal with different applications:
DIN EN 50173-1:2018 General requirements
DIN EN 50173-2:2018 Office buildings
DIN EN 50173-3:2018 Industrial sites
DIN EN 50173-4:2018 Dwellings
DIN EN 50173-5:2018 Data centers
DIN EN 50173-6:2018 Distributed building services
ISO/IEC 11801
The internationally valid series of standards for application-neutral cabling is ISO/IEC 11801. It largely corresponds to DIN EN 50173 and, since November 2017, has also been divided into six parts:
ISO/IEC 11801-1:2017: General requirements
ISO/IEC 11801-2:2017: Office premises
ISO/IEC 11801-3:2017: Industrial premises
ISO/IEC 11801-4:2017: Single-tenant homes
ISO/IEC 11801-5:2017: Data centers
ISO/IEC 11801-6:2017: Distributed building services
TIA-568
In the USA, in addition to the internationally valid ISO/IEC 11801, TIA-568 is also an important cabling standard. It is now in its fifth version. As TIA-568-D, it replaces all previous editions. The values for the cabling components and for the installation and transmission path differ in part from the values of ISO/IEC 11801 and therefore DIN EN 50173.
TIA-568 only applies in North America, unless it is expressly specified in projects.
TIA-568-D is divided into five parts:
TIA-568.0-D: Generic Telecommunications Cabling for Customer Premises
TIA-568.1-D: Commercial Building Telecommunications Infrastructure Standard
TIA-568.2-D: Balanced Twisted-Pair Telecommunications Cabling and Components Standard
TIA-568.3-D: Optical Fiber Cabling and Components Standard
TIA-568.4-D: Broadband and Coaxial Cabling and Components Standard
Installation link (permanent link) and transmission link (channel)
DIN EN 50173 distinguishes between the installation link and the transmission link for the wired line.
The permanent link contains the permanently installed or permanently connected components, so it typically consists of the distribution panel, installation cable and junction box.
The transmission path (channel) is the entire connection between two devices, for example a PC and a switch in the data processing cabinet, including all patch and connection cables (i.e. installation path plus connection and connection cables).
The transmission path is usually only measured during troubleshooting to ensure that all cabling components are working correctly. After the cabling has been installed, only the installation route is almost always measured. The reason for this is simple: if transmission line protocols were required during the acceptance test, the measured connection cables would have to remain plugged into all boxes and distribution panels.
Example of permanent link and channel
Examples of the configurations of the installation route in accordance with DIN EN 50173-2:2018
Cabling sections with 2, 3 and 4 plug connections
According to the standard, a cabling line may contain up to four plug connections. The plug connections on the active components and the terminal devices are not taken into account.
In the simplest case, installation and transmission lines contain two plug connections: one at the distribution panel and one at the junction box.
As an additional plug connection, the line can include a consolidation point near the distribution panel.
junction boxes are included. This is often implemented in open-plan offices, for example. The distributor can also contain a further plug connection if the active component (e.g. a switch) is routed to its own distribution panel; the marshalling then takes place between the distribution panel of the active component and the distribution panel of the tertiary cabling instead of directly between the switch and the tertiary distribution panel. This procedure is referred to as "cross-connection".
Transmission line with four plug connections
Cabling with consolidation point
Sometimes it can be useful to bundle the cables of the tertiary cabling to a common point, the so-called consolidation point,
and place them on boxes or a small intermediate distributor. From this point, cables are routed to movable or permanently installed outlets to which PCs or other end devices are then connected. Consolidation points can be small intermediate distributors, for example.
These can be dividers in suspended ceilings or raised floors in open-plan offices or industrial halls, where floor panels or installation columns with connection sockets are arranged flexibly depending on the changing use. Floor boxes can also be used as collection points if, for example, supply lines to IT furniture, which in turn contain connection sockets, are connected there rather than terminal devices.
Example of cabling with consolidation point
Class and category
DIN EN 50173-1 defines different performance classes both for the wired line and for the individual components of which it consists. The network application class (class for short) always refers to the installed cabling route, the category only to an individual component, for example the cable or the junction box alone, and is measured by the manufacturer or a test laboratory. In the field, measurements must always be made according to class.
Cabling classes according to DIN EN 50173-1:
Class D: up to 100 MHz, suitable for data rates up to 1 Gbit/s
Class E: up to 250 MHz, suitable for data rates up to 1 Gbit/s
Class E A : up to 500 MHz, suitable for data rates up to 10 Gbit/s
Class F: up to 600 MHz, for multimedia applications
Class F A : up to 1.000 MHz, for multimedia applications
Class I: up to 2,000 MHz, for data rates up to 40 Gbit/s
Class II: up to 2,000 MHz, for data rates up to 40 Gbit/s
Component categories according to DIN EN 50173-1:
Category 5: up to 100 MHz, suitable for data rates up to 1 Gbit/s
Category 6: up to 250 MHz, suitable for data rates up to 1 Gbit/s
Category 6 A : up to 500 MHz, suitable for data rates up to 10 Gbit/s
Category 7: up to 600 MHz, for multimedia applications
Category 7 A : up to 1,000 MHz, for multimedia applications
Category 8.1: up to 2,000 MHz, for data rates up to 40 Gbit/s
Category 8.2: up to 2,000 MHz, for data rates up to 40 Gbit/s
Class I/II and Category 8.1/8.2
Class I and II transmission lines are specified for a maximum length of 30 meters. This includes 24 m for the installation cable (installation section) and 3 m each for patch/connection cables at both ends.
Category 8.1 is based on category 6 A. It uses the RJ45 connector in accordance with IEC 60603-7-81 and is backwards compatible with categories 5, 6 and 6 A .
Category 8.2 is based on category 7 A. It is backwards compatible with all categories including 7 and 7 A, but requires a non-RJ45-compatible connector such as TERA according to IEC 61076-3-104, GG45 or ARJ45 according to IEC 60603-7-82.
As IEEE has specified the 40 Gigabit Ethernet variant 40GBASE-T for an RJ45-compatible connector, cabling with Category 8.2 components is extremely rare. After the standardization of 40GBASE-T, the IEEE added the Ethernet variant 25GBASE-T. Instead of 40 Gbps, it offers just over half the data rate at 25 Gbps. It uses cabling components that only meet the requirements of category 8.1 up to 1250 MHz. Conversely, this means that Category 8.1 components must be checked to see whether they meet the requirements of DIN EN 50173-1:2018-10 over the full frequency range up to 2000 MHz. If they only meet the standard specifications up to 1250 MHz, then they only offer just over half the data rate at 25 Gbit/s. The spelling of Category 6 A and Category 6A: Originally a small "a" was used, but later TIA and ISO agreed to use a capital "A". While ISO (and therefore later also Cenelec) lowered the "A" (" A "), the TIA uses it at the same height as the "6": Link and channel according to ISO: Class E A
Link and channel according to TIA: Category 6A link
Component according to ISO: Category 6 A
Component according to TIA: Category 6A
Coordinated systems and mix & match
Although the cabling standards were written to allow components from different manufacturers to be used within the same transmission path, a mix of manufacturers can lead to problems. The standards allow a relatively wide tolerance range and different methods are used in the components to compensate for electromagnetic interference, depending on the manufacturer.
In practice, it is quite common for components that are not matched to each other to lead to signal reflections and thus to high bit error rates. This results in longer response times and the data network operates far below its intended performance.
Tuned and non-tuned systems
Copper data lines
Copper data cables are differentiated according to their performance (component category) and their structure. In the designations for the cable shield, the abbreviation for the outer overall shield of a cable is shown on the left, followed - separated by a slash - by any shielding of the individual pairs. S" stands for a braid of fine wires, "F" for a foil. "TP" stands for the cable type twisted pair.
Copper data cables (twisted pair) are differentiated according to the structure of the cable shield:
S/FTP
common braided shield (S), individual pairs each surrounded by a foil shield (FTP)
F/UTP
common foil shield (F), individual pairs unshielded (UTP)
SF/UTP
common shield of braid and foil (SF), individual pairs unshielded (UTP)
U/UTP
no common shield (U), individual pairs unshielded (UTP)
Copper data cables are available in solid and stranded versions.
Connection technology
The RJ45 plug established itself years ago as the dominant plug for copper networks. The term "RJ45" (or "RJ-45") is not formally standardized, but is used worldwide in practice. The American designation 8P8C is clearer, with the "P" standing for "positions" (positions for contacts) and "C" for "contacts" (actual contacts). The 8P8C therefore also has positions for contacts, all eight of which are actually assigned.
The EN 60603-7 series of standards (international IEC 60603-7) defines the RJ45 in shielded and unshielded versions in various performance levels, from category 5 to category 8.1.
The American standard ANSI/TIA-568 basically provides two different options for connecting eight-core cables to RJ45 sockets and plugs: T568A and T568B. The T568A color assignment originally comes from the military sector and is still prescribed for US authorities.
The color assignment according to TIA does not contradict DIN EN 50173, which refers to DIN EN 50174, which contains two connection schemes as "Option A" and "Option B". From a technical point of view, it does not matter which of the two options is selected. The only important thing is that a cable is laid at both ends according to the same scheme.
RJ45 sockets should have integrated contact overbend protection. If a telephone or fax machine with an RJ11 or RJ12 plug is connected to an RJ45 socket, the outer contacts 1/2 and 7/8 of the RJ45 socket can be damaged. Although RJ11 and RJ12 plugs are similar to RJ45, they are narrower. An integrated contact overbend protection effectively prevents damage to the contacts. This ensures that the highest data rates can be transmitted reliably even after frequent mismating.
Another designation for the RJ12 is 6P6C (connector with six contact positions, six of which are occupied).
RJ45 pin and color assignment
Circular connectors with metric threads of type M12 and M8 are increasingly being used in industrial and transportation applications. The screw locking of these connectors ensures a reliable connection even in the event of vibrations.
The M12 D-coded accepts four cores, fulfills the requirements of category 5 and offers data rates up to and including 100 Mbit/s.
With the same dimensions as the M12-D, the M12 X-coded connector accommodates four pairs of wires, which are also fully shielded from each other in the contact area by a shielding cross. The M12-X fulfills the requirements of category 6 A and offers data rates up to and including 10 Gbit/s.
Like the M12-D, the M8 has four cores, meets the requirements of category 5 and offers data rates up to and including 100 Mbps. However, it is significantly smaller than the M12 and is therefore suitable for applications where space is limited.
The M12x1 X-coded circular connector offers data rates up to and including 10 Gbit/s.
Circuit board and module technology
Increasingly stringent technical requirements for the cabling route and, at the same time, ever greater time pressure during installation and processing have been successfully resolved with modular technology. Whereas junction boxes and distribution panels were previously preferably manufactured on the basis of printed circuit boards (PCBs) onto which the connection blocks and RJ45 sockets were soldered, modular technology involves mounting individual, separate RJ45 sockets on the individual cable ends. Each cable is therefore connected to separate modules at both ends. The sockets are then simply snapped into the distribution panel or junction box. The modular technology results in better transmission values and a significant time saving when laying the cables and installing the boxes and distribution panels. It also offers the advantage that individual cable sections can be retrofitted more easily and therefore more cost-effectively than with conventional distribution panels. Laying cables can no longer just be connected to boxes and modules. If installation cables are terminated directly with a plug, they can be fed directly into the weatherproof housing of surveillance cameras, for example. There is no need for an additional junction box near the camera. This advantage is also used for system cabling in industrial production, and home office cabling can also dispense with junction boxes, for which there is often no space. Good connectors can be assembled on site with little effort and are universally suitable for applications ranging from telephony to 40 Gigabit Ethernet.
The MFP8 from Telegärtner: tool-free field assembly in less than 60 seconds and suitable for networks up to 40 Gigabit Ethernet
Power over Ethernet (PoE)
With Power over Ethernet, the end devices are supplied with power via the data line. The IEEE standardization committee has defined the technology required for this in the IEEE 802.3 standard and its supplements: With PoE and especially with PoE+ and 4PPoE, high-quality connection components (junction boxes / distribution panels) are extremely important, as the delicate contacts now carry data and power simultaneously. The design of the contacts is of particular importance. If an RJ45 plug connection is disconnected while the end device is still being supplied with power via the data line, breakaway sparks occur which damage the delicate contacts of the plug and socket. The sparks cannot be technically avoided, so it is important to design the contacts in such a way that the area in which the data is transmitted is far away from the area in which the damage caused by tear-off sparks occurs. This ensures that the full data rate can still be transmitted even after repeated unplugging under load.
De-embedded/Re-embedded
Cabling for high-performance networks requires sophisticated measurement technology. This applies in particular to the components that are to transmit the highest data rates in their interaction. The de-embedded measurement method was developed for category 6 components. This involves measuring a socket against 12 different reference plugs in order to record the entire bandwidth for the mix & match, the mixing of products from different manufacturers within a cabling route, which is so popular in Germany. Naturally, different values are obtained for the different plugs and results must be achieved within the standard specifications with all of them.
The de-embedded measurement method is sufficiently accurate for category 6 components up to 250 MHz and data rates up to 1 Gbit/s. However, despite the great effort involved, it is not reliable enough for measuring category 6A components up to 500 MHz and data rates up to 10 Gbit/s. While the de-embedded method looks at a socket to be tested individually (to embed, de-embed), the re-embedded method looks at the socket as a whole. The re-embedded measurement method uses a reference plug whose values have been determined very precisely. With this measurement method, two measurement recordings are connected to a network analyzer. One contains a permanently soldered socket for the reference plug, while the socket to be measured is connected to the second with short twisted wire pairs. The two receptacles are then plugged together and measured.
However, the re-embedded test setup with several boards in accordance with IEC 60512 is still not precise enough for Telegärtner: The Telegärtner test laboratory connects the test socket board directly to the network analyzer via coaxial cables. The advantage: Interfering NEXT influences are minimized, as are interferences between wire pairs in the case of test leads with twisted wires. The special measurement setup with coaxial cables enables even more accurate measurement results than with the setup according to IEC 60512.
Telegärtner Real-Time Re-Embedded Cat.6 A
With an 8-port network analyzer with re-embedding calculation method, the real-time/re-embedded measurement setup provides a real-time evaluation of the components. This allows the effects of changes to measurement objects to be evaluated in real time. The extremely time-consuming measurement of all pair combinations is therefore no longer necessary.
Category 6 A patch cable
Patch cables are neglected in many installations - with serious consequences, as the most powerful infrastructure falls far short of its potential if low-quality patch cables reduce the quality of the overall transmission link. But how can you tell if you have a high-quality patch cable in front of you? Cat.6 A components have been measured in the laboratory for some time using the re-embedded measurement method, but not patch cables - the physical conditions made measurement difficult. Once again Telegärtner led the way: The Telegärtner laboratory was the first to be able to measure Cat.6 A patch cables. This was made possible by a measurement adapter developed in-house. The measurement setup is more sophisticated and precise than the international standards for measurement technology prescribe. Telegärtner uses the real-time/re-embedded measurement method, in which all four pairs are measured simultaneously with an 8-port network analyzer. The sophisticated set-up without measuring transformers (baluns) provides more precise measurement results and is trend-setting for testing high-quality patch cables. This ensures that the transmission path can transmit the full data rate.
According to DIN EN 50173-1:2018-10, the standard-compliant designation for patch cables is "patch cord" or "device connection cord" - depending on whether the patch cable is used to connect two distribution panels or to connect devices.
