Classic telephone systems, operated by the company itself, with long-term contracts are discontinued models. The high cost of installation and operation, and the limited scalability are no longer appropriate. Telephone systems, which are five to ten years or longer in use hold, with non-technical innovations and changing business requirements more step. The Innovation cycles in this field are now so short that technologies already installed stale immediately after the start. Although individual functions via firmware update can still be supplemented, but so are the technical possibilities largely exhausted.