NGN is short for Next Generation Network. To put it simply, NGN means the shift from the common telecommunications networks to data transfer via Internet.
What does NGN offer for consumers then? NGN providers offer their costumers the opportunity to use their telephone, Internet, and sometimes even TV through the same access. At first glance, a single access sounds only convenient and is also cheaper in most cases, because many NGN providers offer national flat rates for landline calls as well as an excellent quality of connections and data transmission. So where is the catch then? If you switch to an NGN provider, you cannot use the cheap call-by-call-numbers for calls to foreign countries or other mobile networks. However, callthrough services like DCalling still work in this case.