In our blog you will find information, technical articles, practical tips and news of network technology and data communication. 


wet cable reel

What happens after copper cables have become wet?

22.02.2024 | Indoor copper cables shall not become wet. However it can happen that a cable drum accidentially stands in the rain or cables get wet by accident inside of a building. What impact does that have on the cable’s transmission performance?

E2E Links

End-to-end links recognized by international standards

20.02.2024 | EN 50173-20 recognizes various types of end-to-end links as “alternative cabling configurations“.

Image: Differnce between GHMT and DIN

Fiber optic connector grades compared to GHMT PVP Level 2

20.02.2023|  What’s the difference between fiber optic connector grades specified by IEC 61753-1 and GHMT PVP Level 2? Read on to learn about the differences.

Measuring device


19.02.2024 | Legth testing of a link serves two purposes: To make sure the length of the cable does not exceed the limits specified by the standards and to use the measured length to bill the customer for the cable installed. There are a few points to be minded to make sure the tested lenght is accurate. Read on to find out about them.


Nominal Velocity of Propagation (NVP)

05.01.2024 | No other parameter is discussed that often as NVP as plays as it is important for testing the correct length of a link and thus for billing the customer correctly on it. Read on to find out what NVP is all about and how it is determined in accordance with the relevant standards.

FFP Toolkit

Field-installable fiber optic connectors

05.01.2024 | Gone are the times when installing fiber optic connectors on a cable was for specialists only. Modern field-installable connectors can be installed on site as quickly and easily as connectors for copper cables.

fiber optic connectors

Fiber optic connector grades

05.01.2024 | Good fiber optic connectors have low attenuation and high return loss. But what exactly is “good“? IEC 61753-1 specifies performance grades for fiber optic connectors.


White paper “IT connectors for harsh environment"

05.01.2024 | IT connectors that are desingned for indoor use must not be used in outdoor applications. This includes IP67 rated industrial connectors. This white paper focuses on different operation conditions of IT connectors and the protective measures that go with it.

RJ45 Outlet

Why are RJ45 modules installed upside down in sloped faceplates?

05.01.2024 | Many RJ45 modules have their component category like “Cat.6A“ printed on the front. Why are they installed with the printing upside down in sloped faceplates? Read on to find out why.

installation cables

Installing outdoor cables inside of buildings

05.01.2024 | May outdoor cables be installed inside of buildings? What is written in the standards?

rj45 module

Wire map (continued)

24.11.2023 | Half of the eight wires in a cable have a white insulation. Happens from time to time that wires are swapped. This issue and the following ones will focus on the different type of “swaps” and what to do against it.

RJ45 outlet

The difference between 110 connect and LSA+

23.11.2023 | There are two versions of IDC contacts around: 110 connect and LSA+. At first glace they resemble each other, but they differ in important details. Read on to find out the differences between the two IDC types and why one shouldn’t mix the punch-down tools.

IDC Connection Blocks

Connect wires to LSA+ connecting blocks fast and particularly reliably

20.11.2023 | It sometimes happens that wires slip out of IDC contacts although everything looked fine. This issue shows a simple and proven trick how to connect wires fast and particularly reliably to LSA+ contacts.


White paper “Single Pair Ethernet and Power over Data Lines“

24.11.2023 | With Single Pair Ethernet, Ethernet becomes the uniform communication protocol on all levels of industrial automation and building automation. Some standards are still under progress. This white paper gives an overview on the status quo of standard and technology.


New data centre cabling standard ISO/IEC 22237-5

23.11.2023 | In the past days, a “new ISO/IEC 22237-5 standard for data centre cabling“ made network designers and installers unsure. However, there is nothing to be unsure about as neither this particular standard nor its content are new. Read on to find out more about this standard.

E2E Tester

Can patch cords be tested performing just a channel test?

20.11.2023 | Patch cord have plugs on each end, channel test adapters have jacks. Should be a perfect fit, shouldn’t it? Unfortunately, it isn’t, as it gives you completely wrong test results. Read on to find out why.

IPC COntacts

The difference between IDC and IPC contacts

24.10.2023 | IDC and IPC contacts terminate the wires of a cable in an outlet, in a module or in a plug. Read on to know the difference between the two contact types.

Standards for Ethernet

IEEE 802.3 Standard for Ethernet

24.10.2023 | IEEE 802.3, 802.3at, bt, af, … IEEE numbers can be a bit confusing. In this article we focus on the numbers of the IEEE Standards für Ethernet.


“Shorties“, shielded and unshielded

01.10.2023 | Particularly short field-installable RJ45 plugs and modules come in very handy in confined spaces. This very often happens in retrofit installations in old building. Short Cat. 6A plugs and modules are available in shielded and unshieded versions. Both are designed to transmit 10 gigabits per second. Read on to find out where to use which version.

IDC Contacts

Can 110 contacts be terminated with an LSA Plus punchdown tool?

24.10.2023 | Patch panels, outlets and RJ45 modules typically have either LSA Plus or 110 contacts. Can the LSA Plus punchdown tool also be used for 110 contacts and vice versa? Read on to find the answer.

Wire manager

Wire map

24.10.2023 | The wire map test checks whether all wires of a cable are connected properly on both ends of the cable and whether there is a short or an open. The various issues the wire map tests can detect will be discussed in this and in the following issues.

N connector series

Push & Crimp: N and SMA Connector

1.10.2023 | Telegärtner presents an innovation in the field of connection technology with the N connector in the Push & Crimp version. The Push & Crimp series is characterized by quick, easy and reliable installation on site, no soldering is required. The availability of simple tools for cable preparation further simplifies the installation process. Reliable sealing and protection against environmental influences is guaranteed with the enclosed shrink tubing (IP67).

RJ45 modules

End-to-end links – End-to-end link (E2E link)

21.09.2023 | Wherever telecommunication outlets and patch cords are unwanted, electronic devices are connected to the horizontal cable. Modular plug terminated links (MPTLs), direct attach cabling (DAC) and end-to-end links (E2E links) have proven their worth. This article focuses on end-to-end links.


Where can I buy standards?

05.09.2023 | Standards are important – and expensive. Few people know that some standards can be obtained or at least be read at no cost.


White paper “Fiber Optic Connection: FTTH, FITB and Beyond“

05.07.2023 | More and more homes and commercial buildings get a fast internet connection via optical fibers. But how shall the buidings be cabled in order to bring the high data rates to the electronic devices? This white paper shows typical scenarios and proven solutions.

Pass and Fail

Test results with a star: *Pass and *Fail

20.09.2023 | Sometimes the tester adds a star to the test results. Read on to find out what *Pass and *Fail mean and about their impact on validating a link.

Fiber Optic Patchkabel

Why are fibers in a cross-over patch cord parallel?

05.09.2023 | Optical fibers run parallel in a cross-over patch cord. Are they really parallel or are they somehow flipped? 

Crimp Tool

Right down: Parellel presser and pipe wrench

04.09.2023 | Why would you buy a parellel presser when you already have a pipe wrench? The answer is easy: You are quality-conscious. Read on to learn more.

RJ45 outlets and modules

RJ45 outlets: Modules versus PCB based outlets

04.07.2023 | There are two versions of RJ45 outlets available: With modules that are snapped into a bezwo or a frame and with connecting blocks that are soldered into a common printed circuit board. Both versions have their specific benefits and drawbacks. 

RJ45 patch cords

End-to-end links – Direct attach cabling (DAC)

28.06.2023 | Wherever telecommunication outlets and patch cords are unwanted, electronic devices are connected to the horizontal cable. Modular plug terminated links (MPTLs), direct attach cabling (DAC) and end-to-end links (E2E links) have proven their worth. This article focuses on direct attach cabling.

test report correct

Additonal details in a test report

30.06.2023 | In a test report there have to be the test results and the values specified by the standards. That’s a no-brainer. However, in a test report there has to be a lot of additional information. Read on to learn the details.

red and black connector boot

What do red and black connector boots on fiber optic patch cords mean?

04.07.2023 | Fiber optic patch cords with single-fiber connectors often have one connector with a red cable boot and another connector with a black one. What does that mean? Read on to find the answer.

American Standards

Important American standards

30.06.2023 | The last issue of this column provided and overview on important global standards for IT cabling. This issue focuses on American standards

Digital Ceiling

White paper “Digital Ceiling“

30.06.2023 | The white paper focuses on digital ceiling applications and on the IT infrastructures that go with them. Newsworthy!

jacket collour

Fiber optic cable jacket colours

29.06.2023 | There are standadized colours not only for optical fibers but also for the cables that hold them. The benefit of it: One can tell the fiber type that’s inside of the cable at first glance. However, not all cable manufacturers follow the standard.


Important global standards

29.06.2023 | The last issue of this column provided and overview on important European standards for IT cabling. This issue focuses on global standards.

RJ45-patch cable

End-to-end links – Modular plug terminated link (MPTL)

28.06.2023 | Wherever telecommunication outlets and patch cords are unwanted, electronic devices are connected to the horizontal cable. Modular plug terminated links (MPTLs), direct attach cabling (DAC) and end-to-end links (E2E links) have proven their worth. This article and the next two ones focus on these three link types in detail.

wiring sheme

What’s the difference between T568A and T568B and why are there two wiring shemes?

29.06.2023 | Do copper cable have to be connected according to T568A or T568B? And why do the standards specify two wiring schemes? Read on to find the answer.


What has to be tested according to standards?

29.06.2023 | When it comes to testing, different cabling standards have different requirements what has to be tested. Read on to learn about the test parameters recognized by the standards.

Book about structured cabling

Reference book "Powerful IT Infrastructures:
Structured Cabling - FTTO & POL

22.06.2023  | Classic structured cabling, fibre to the office (FTTO) or a passive optical LAN (POL)? This practical book gives professional installers, planners and users an overview of current cabling infrastructures and compares their respective special features.


Fiber colour codes for fiber sequence

25.05.2023 | Unlike commonly believed, IEC 60304 does NOT specify any fiber sequence. The standard just specifies twelve different colours. The sequence of these colours is specified by other standards which differ from each other.



RJ45-Stecker and SPE

The difference between Power over Ethernet (PoE) and Power over Data Lines (PoDL)

22.05.2023 | Both, PoE and PoDL can power Ethernet devices over data cable. However, the two are not compatible at all – read on to find out why.


Different Types of Testers: Verifyer, Qualifyer and Certifyer

22.05.2023 | What is the difference between a verifyer, a qualifyer and a certifyer? Find out the difference and learn where to use which of them.


Important european standards

22.05.2023 | With a nearly countless amount of standards available, it is not alway easy to keep things in perspective. Please find an overview of important European standards on IT cabling here.


White paper “High-performance IT cabling for Schools“

22.05.2023 | The white paper explains planning recommendations and product solutions for robust, future-proof and economic IT cabling in schools – straight-forward and easy to understand.

SC Adaptors

Are there couplings to connect SC and LC fibre optic connectors?

19.05.2023 | Can old SC and new LC plugs be mated in the same adaptor like SC and ST? Read on to find the answer.

Outdoor Connectors

IP67 is not enough for outdoor connectors

25.04.2023 | P67 rated industrial connectors are protected against ingress of dust and humidity. Outdoor applications, however, have some more and much harder requirements. IP67 is not enough – read on to find out why.

flush-mount outlets

No kinked cables when installing flush-mount outlets

17.04.2023 | A long piece of cable protruding the back box it easier to connect it to a flush-mount outlet, but it can’t be pushed back far enough after connecting it and so it will kink. A short piece of cable doesn’t kink, but connecting it to an outlet is a nightmare. Outlets that have connecting blocks on the front solve this problem.

Hand pressing a question mark

Why are there no RJ45 connectors of category 7 and 7A, but of category 8.1?

22.02.2023 | RJ45 connectors of category 8.1 do not meet the requirements of category 7 and 7A. Why? Here you will find the answer.

Examples of the different configurations

Different types of links

22.04.2023 | EN 50173 and ISO/IEC 11801 recognize different link types. Read on to learn about the different types and how to test them.




Do we really have to? Obligation to obey standards?

27.04.2023 | Standards have to be obeyed, that’s what they are there for, aren’t they? Unfortunately, it’s not that easy. The correct answer like so often is: It depends. Read on to find out on what it depends.



Who Standardizes What? Standards Bodies

06.04.2023 | There is a multitude of IT cabling standards: EN, IEC, ISO/IEC, TIA and IEEE are publishing regularly standards on cabling, components, transmission protocols and testing. Get an overview here.



wall-mount outlets

“Minimally invasive“ Retrofitting of IT cabling in Homes

11.04.2023 | Retrofitting of IT outlets in homes is not an easy task. Comprehensive renovating or reconstructing allows milling wall slots and installing IT cables in duct. But there is a much easier way that eliminates the need for renovating.

Cable jacket materials

Cable jacket materials

06.04.2023 | Twisted-pair, coax and fiber optic cables are used in many different applications, which makes different jacket materials necessary. Among the most important ones are LSZH, PVC, FEP, PUR and PE. Read on to find out the specific advantages and drawbacks of the different jacket materials.

Test Measurement

Testing Copper Links in Structured Cabling
Introduction and Types of Signals

11.04.2023 | Despite careful workmanship an error creeped into the cabling and the cable tester mercilessly reports FAIL. What now? The series of articles in this column explains the different test parameters and gives useful advice for error correction.