Init7 Blog - Overbooking - how providers divide up the bandwidth

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2024-09-25 10:00:04

Most providers advertise their Internet subscriptions with the maximum available bandwidth – in addition to the price. These two parameters are easily comparable for customers and are often the decisive criterion when making a choice. In the past, when fiber optics did not yet exist, Internet connections were built using two competing technologies: DSL (Digital Subscriber Line) in various forms (ADSL, VDSL, g.Fast) on the two-wire copper cable used for conventional telephony, and cable Internet on the coaxial cable used for cable television. Both technologies have in common that the transferable frequencies on the respective cable are physically restricted, which limits the achievable bandwidth.

As most residential customers require more bandwidth for downloading than for uploading, the available frequencies were divided up accordingly, resulting in asymmetry: 100/20 Mbit/s with DSL offers 100 Mbit/s bandwidth for downloading, but only 20 Mbit/s bandwidth for uploading. This restriction also applies to cable Internet, although the achievable bandwidth is greater with cable. The DOCSIS 3.1 standard used in Switzerland could theoretically reach 10/1 Gbit/s, while the DSL technologies currently in use stop at 500 Mbit/s.

In contrast to cable and DSL, fiber optics knows no limits. It is therefore not surprising that almost all network operators rely on fiber optics and ignore newer cable technologies such as DOCSIS 4.0 or 4.1. A fiber optic network is much easier to operate and also consumes less electricity, which is of course much more economical in the long term, even if the construction of fiber optics requires high investments.