SDSL Internet for your business? Check out what ITH Net has to offer!

You have a business, and you need internet that works equally well both ways – both when you upload large files and when you download them. Do you send backups to the cloud? Do you share important documents with clients? If so, traditional home internet (i.e. ADSL) may not be enough. It’s a bit like a highway with five wide lanes for downloading and only one narrow lane for uploading. It’s very good for watching movies, but if you’re the one with something to upload – you might get stuck in traffic. That’s when SDSL steps in.

What is SDSL?

SDSL, orSymmetric Digital Subscriber Line, is a technology that was developed in the late 1990s with businesses in mind. Its main principle was simple: equal upload and download speeds. Whether uploading or downloading something, the Internet was supposed to operate at the same, stable speed. This was crucial for companies that made heavy use of video conferencing, remote access to resources, or hosted their own email servers and websites.

How did the SDSL work?

SDSL, like other DSL-based technologies, used ordinary copper telephone cables that were often already in buildings. There was no need to dig new trenches or pull fiber optic cables, which 30 years ago was a major advantage and cost savings. Special modems “processed” the data so that it could travel over these copper wires in both directions at the same speed. All of the available bandwidth was dedicated to data only, so it was not possible to talk on the same line at the same time to talk on the phone and have Internet as with some other technologies.

Why did companies “like” it?

• Equal power in both directions

  That’s the biggest advantage. No more frustration when downloading went at lightning speed, but sending data, such as an email with a large attachment, took an eternity.

• Stability and reliability

  Often it was a dedicated link, which meant you didn’t share it with your neighbors. Your business was guaranteed a constant speed that didn’t depend on what others were doing.

• Low infrastructure requirements

  It worked on existing telephone cables, so installation was usually quick and cheaper than building a new network.

• Ideal for business

  Video conferencing without stuttering, fast access to corporate servers via VPN, efficient transfer of backups – SDSL was tailor-made for business needs.

Why is SDSL a rarity these days?

Despite many, SDSL has quite a few limitations that make it a “historic” technology today. What has made it much less common today?

• The farther your company was from the telephone exchange (i.e., the place where the signal was sent to the operator’s network), the slower the Internet was. After a few kilometers, the speed dropped dramatically.

• Although symmetrical, SDSL’s maximum speeds were much lower than what today’s technologies (such as fiber or even VDSL) offer. We are talking about a few megabits per second, not hundreds or gigabits.

• Paradoxically, although it worked on existing cables, the dedicated nature and symmetry assurance meant that SDSL was often more expensive than the popular asymmetric digital subscriber line.

SDSL was once a revolutionary solution for business that solved the problem of Internet asymmetry. It was great at a time when fiber wasn’t as widely available, and businesses needed equal strength for sending and receiving data.

Today, however, due to the rapid development of technology, most companies are opting for fiber optics, which offer incomparably higher speeds, both symmetrical and asymmetrical, and are much more reliable over long distances.

Where can SDSL be found?

Although SDSL is already a senior among Internet technologies, it would be wrong to say that it has disappeared completely. Although increasingly rare, you may still run into them in very specific situations:

SDSL in “white spots”

There are places where bringing fiber optic cable would be so expensive and complicated that it just isn’t worth it. In remote areas, in very small villages, or where the ground is so difficult to dig. In such places, SDSL (or its slightly faster cousin, SHDSL) may be the only salvation.

Companies unwilling to upgrade infrastructure

Sometimes companies have age-old systems at their site that still work, but just need a symmetrical connection over copper to do so. For example, these could be older monitoring systems, specific alarms, or devices that send measurement data. Replacing all this with newer, fiber-optic solutions would be too costly or complicated for them.

Symmetric digital subscriber line as a “lifeline”

Some companies already have super-fast fiber, but they still want a very low-cost backup link just in case. One that will allow for the bare minimum if the fiber fails. Sometimes then they’ll think about SDSL/SHDSL over copper, because it’s a different technology than fiber. But frankly, even here it’s more common to just go for the cheapest ADSL or mobile internet (LTE/5G).

Digital subscriber line as a relic

Telecom operators sometimes just keep SDSL services for those customers who have had them for years and still use them. But you certainly won’t find them in new offers for companies that are just connecting the Internet.

Why do we say that SDSL is a “thing of the past”?

Despite these niche applications, the term “obsolete” seems about right. SDSL has ceased to be a technology for “the masses” because the speeds offered do not meet user expectations. In today’s world, where everything is “in the cloud” and requires instant transmission, SDSL simply can’t keep up.

In short, SDSL has not disappeared completely, but its role today is marginal. It can be found in very specific situations where there is no other option or where the cost of upgrading is too high. For most companies and anyone planning a new Internet, SDSL is now a closed chapter.

SDSL: pay attention to this!

If a provider offers you “SDSL” today, make sure they don’t happen to be referring to the more modern but still less common SHDSL technology, or simply find out if fiber would be a better and more future-proof solution for your business.

Digital subscriber line For your business? Check out what ITH Net has to offer!

Although SDSL is more of a technology of the past, the idea of equal, stable speeds in both directions is still very much in vogue – especially for businesses. If you’re looking for a reliable connection that fits the needs of your business, we’re happy to offer turnkey solutions. At ITH, we understand these needs very well. We offer internet designed with businesses in mind – fast, stable and available where others fail.

You don’t need to know about technologies – just tell us what you need, and we’ll do the rest. We use a modern infrastructure that allows us to receive and send data at the same speed, which translates into stability and reliability in daily operations.

Glossary of DSL Standards

ADSL (Asymmetric Digital Subscriber Line) – Asymmetric Digital Subscriber Line.

SDSL (Symmetric Digital Subscriber Line) – Symmetric Digital Subscriber Line.

SHDSL (Single-Pair High-Speed Digital Subscriber Line) – Single-pair High-Speed Digital Subscriber Line.

VDSL (Very-High-Bit-Rate Digital Subscriber Line) – Very High Speed Digital Subscriber Line.

VDSL2 (Very-High-Bit-Rate Digital Subscriber Line 2) – Very High Speed Digital Subscriber Line 2.