(V)DSL

DSL (Digital Subscriber Line) is such a classic among the various Internet connections that the acronym is practically synonymous with online access. Development of this technology began in the early 1990s. Technical progress such as VDSL (Very High-Speed Digital Subscriber Line) means that theoretical transmission speeds of up to 300 Mbps are possible today. Typical DSL contracts for household customers are usually advertised with speeds of up to 250 Mbps.

The greatest strength of DSL technology lies in its availability: An Internet connection via DSL is available in nearly all homes now, and at speeds of about 250 Mbps there is enough bandwidth for all typical application scenarios – including online gaming and high-resolution video streaming. With this technology, however, there is no longer any significant increase in transmission speeds to be expected.

Cable

A cable connection – this designation can be confusing at first because, aside from mobile services, all Internet connections use cable connections. "Cable" refers explicitly to the use of television cables for data transmission. This is based on the DOCSIS standard and theoretically allows for transmission speeds in the gigabit range.

Much like DSL connections, cable connections benefit from easy availability: If there is no cable television, usually the line can also be used as an Internet connection. The trade-off is that the speed can fluctuate wildly. Since all connected households share the available bandwidth for Internet as well as for television, the transmission speed is rarely stable, and noticeable drops in speed are possible particularly during peak TV-watching times.

Fibre optics

State-of-the-art fibre-optic connections have significantly better performance. Their advantage: While DSL connections use conventional copper cables, these use their namesake fibre-optic cables. That makes the connection less susceptible to interference and above all faster: Transmission speeds extending into the two-digit Gbps range are possible.

However, how fast a fibre-optic connection really is will vary from case to case. In particular, fibre-optic networks are categorized into three basic architectures:

• FTTC (Fibre to the Curb): The fibre-optic cable ends in the distribution box "at the curb", whereas the rest of the signal's path into the house or flat is over conventional telephone cables, which significantly slows down the connection.
• FTTB (Fibre to the Building): The fibre-optic cable ends in the home. As a result, the transmission speeds actually achieved depend on what wiring is used for the final stretch of the transmission path – for example, a telephone cable or an Ethernet cable.
• FTTH (Fibre to the Home): The fibre-optic cable extends to the residential connection socket in the home's basement or living area and thus enables the fastest transmission.

A fibre-optic connection is regarded as the gold standard for high-speed connections, so it is the first choice for households with high demands on the available bandwidth. Its actual speed, however, depends on the architecture of the local infrastructure.

The ABCs of fibre optics from AON to WDM-PON

Incidentally, as if the various architectures of fibre-optic connections were not complicated enough, there are even more differences. In particular, there are different technical types for establishing the connection with fibre optics. The most important are AON (Active Optical Network) and PON (Passive Optical Network). In the case of AON, for each household or user there is a separate fibre-optic cable up to an active distribution point. Components such as switches enable the individual connection and ensure that individual subscribers do not have to share the bandwidth. At the same time, they increase the costs and maintenance effort. PON, on the other hand, functions with passive components such as splitters, which distribute the signal to multiple households. This solution is more cost-effective, but also means that multiple users share a line and thus also the available bandwidth. This leads to problems like those with a cable connection when a rather large number of users are active.

Within the PON family, in turn, there are various standards: GPON is currently the most widespread and offers download speeds of up to 2.5 Gbps. For higher requirements there are XGS-PON (10 Gbps symmetric) and NG-PON2, which offer more capacity by simultaneously using multiple wavelengths. WDM-PON goes even further by not sharing the bandwidth, but in return there is an increase in technical expenses.

Mobile phone services: LTE and 5G

With standards such as LTE and 5G, state-of-the-art mobile phone networks reach transmission speeds so high that they can even serve as residential Internet connections. To be specific, LTE networks enable transmission speeds of up to 300 Mbps. 5G networks reach even as high as gigabit speeds. Mobile wireless connections are suitable particularly when other types of Internet connections are not available at home or only offer a low transmission speed. The costs incurred should be checked closely before a mobile data contract is signed, as heavy use of high-speed mobile services is usually much more expensive than a conventional Internet connection.

Cable versus wireless: How fast are Internet connections really?

The various types of Internet access each have individual strengths and weaknesses, as well as different theoretically possible bandwidths. But which of those is actually available in practice? Data on this is collected by companies such as Ookla, which provides the popular speed test at https://www.speedtest.net/. According to the "Speedtest Global Index" from Ookla in March of 2025, mobile wireless connections have an average global performance of 91.50 Mbps for downloads and 13.62 Mbps for uploads. Broadband fixed-line connections, in turn, have an average global performance of 99.92 Mbps for downloads and a significantly higher 54.66 Mbps for uploads. Here it is important to note that various types of connections are lumped together under the broadband connections. These include, for example, DSL as well as fibre-optic and even satellite connections.

So the information has to be used with caution, and the actual performance fluctuates anyway depending on the quality of the local architecture. Despite this, the numbers show that, in principle, all types of Internet connections are suitable for fast online connections. The choice of the right connection therefore depends on the individual case.

devolo: Get the most out of your connection

But regardless of how good a residential Internet connection is, what matters in the end is what transmission speeds are actually available to the client devices. That's because the bandwidth available in the home will not automatically reach client devices such as computers, smart TVs and game consoles without losses. A weak home network can even slow down broadband connections so much that video conferences and online streaming look like a slideshow. The German experts at devolo have a remedy, as they have been offering solutions for customised optimisation of home networks since 2002. With devolo Powerline adapters, Wi-Fi repeaters, the new 5G router and additional devolo products, the bandwidth will reach every room, whether wirelessly or by cable.