What does landline telephony have to do with the cloud?

Generally speaking, a "cloud" is primarily a collection of IT resources such as computers, storage or applications that can usually be used by various users via the Internet and independently of specific devices. One could therefore also refer to it as a "computer or data cloud". This approach reduces costs for individual users, as they do not need to operate their own infrastructure in the form of computers etc. for their applications and functions, but can instead rent these on a cloud as required. It also allows for a quick response to changes in demand, as resources can be flexibly distributed between different users depending on demand. A well-known example of a large cloud that can be used by a wide variety of customers (from private individuals to large companies) is AWS, Amazon's cloud (Amazon Web Services).

The term "cloud" often raises concerns: it implies that telephony is freely and publicly accessible and no longer secure. This stems from the fact that the term "cloud" is usually associated with a so-called "public cloud", such as Amazon's AWS mentioned above. Here, too, the data and access of individual customers are strictly separated from each other, but the infrastructure is shared.

However, there are also so-called "private clouds": Here, too, a collection of IT resources from various services is used, but this cloud is operated exclusively by and for one organisation or company. In this context, "cloud" simply refers to a specific type of IT infrastructure that, as described above, allows for a quick and flexible response to changes in requirements such as peak loads (in telephony, for example, at Christmas). However, the cloud is not accessible to other customers, neither the data processed there nor the actual infrastructure.

When Deutsche Telekom refers to the "cloud" or "cloudification" in relation to landline telephony, it always means the latter. As before, the "telephony cloud" is Deutsche Telekom's own "data centre" in which no applications from other customers run and whose resources cannot be used by other customers; only the type of IT infrastructure is based on the "cloud" principles described above.

The term "access via the Internet" is often associated with the idea that all this traffic runs side by side in a virtually indistinguishable manner and that the data of all services can therefore be easily tapped or falsified, as there are no longer separate "lines" for telephony, for example.

However, additional precautions are regularly taken for particularly sensitive data transfers. Take online banking, for example: the necessary security is ensured through encryption, authentication via passwords or PINs, and the use of "virtual" lines (known as tunnels). The same mechanisms are also used in Deutsche Telekom's landline telephony to prevent unauthorised access to the "cloud" and interference with data traffic to the cloud.

There are various cloud solutions with different security levels. Sensitive telephone data is specially protected in Telekom's landline network. This applies in particular to all internet tariffs, such as the classic DSL tariffs and business fibre optic tariffs.