What is the difference between ISDN and DSL?

In order to use the internet, you need a connection and the possibility to transmit data. Well-known solutions for this are ISDN and DSL. But what exactly is the difference?

Advanced technology: Product features and benefits of DSL

DSL is the abbreviation for Digital Subscriber Line. The connection to the internet is established via the telephone line, whereby a DSL splitter (broadband connection unit) is usually the interface for both connections. As a rule, new lines for the customer can be dispensed with, since the conventional copper twin wires of the telephone network can be used. According to Deutsche Telekom, however, IP-based connections for DSL access are to be switched over to as of 2018. In addition to the telephone connection, subscribers require a DSL modem. One advantage is that you don’t have to connect a real landline connection to the internet. Advanced providers rely on VoIP and internet telephony (more about IP Telephony).

DSL and fiber optics as high-speed broadband connections, replace the technology of a few years ago, which in the form of modem and ISDN enabled comparatively slower surfing at home and during operation. DSL - the classic among the internet access points used throughout Germany - made it possible for the first time to make phone calls and surf the Internet at the same time. The parallel use of the Internet and the telephone adds the advantage of higher speed. With a speed of up to 16 Mbps, DSL is around 250 times faster than ISDN. In addition, DSL enables customers to protect themselves against dialers and hidden costs and save money by offering very low-cost double flat rates for Internet use and telephony. In the meantime, various companies are replacing the DSL connection with even faster and more practical variants such as VDSL (fiber optic technology) or WLAN for wireless internet via radio and thus for mobile internet access.

The reliable evergreen: ISDN

ISDN stands for Integrated Services Digital Network. This is a digital communication network in which analog exchanges have been replaced by digital technology. This makes it possible to manage two connections or calls at the same time and simplifies data transmission, when using the internet. Compared to the telephone modem, the ISDN connection is more convenient and faster. With two basic connections, the user can, for example, make a telephone call and send a fax or surf the web at the same time. The data transmission rate for an ISDN connection in Germany is 64 kbps, the average bit rate is up to 160 kbps.

Those who live in the urban areas have access to DSL or even fiber optics, but despite its widespread use, the connection is still not available everywhere in Germany or can only be used with low quality. ISDN is therefore still very welcome in rural areas. With this internet connection, it is not important that there are only short distances between the exchange and the device/access. Sometimes DSL in villages can only reach speeds of 1 to 2 Mbps, so ISDN access is preferable. Generally speaking, the comparison between ISDN and DSL shows that DSL is faster and offers more possibilities, but the availability of DSL still needs some work. As most businesses are located in cities and rely on fast internet connections, DSL is preferable.

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