With businesses seeking to reduce costs and improve quality of service, the market is moving from ISDN (the system which supports the desk phone), to Voice over Internet Protocol (VoIP), a system which facilitates voice calls via your internet device. In fact, BT has been in the process of retiring ISDN since 2015 and has announced end of life by 2025. ISDN will no longer be offered to new businesses from 2020. If you are rather attached to your old desk phone, have a think about what you could replace it with instead. Referring to a recent study presented by Bloomberg, Business Insider recently reported,