The alternative for a PSTN landline is Voice over Internet Protocol (VoIP) or Digital Voice, a solution that transmits voice calls and data using an internet connection.
The swap-over will require that the landline phone is no longer plugged into the present BT wall socket but into the router (possibly using an adaptor) and your broadband
connection enabled for VoIP by your Internet Service Provider (ISP).
There is advice from OFCOM . Your landline provider will contact you to let you know when the process to migrate from your old landline to your new telephone service will apply to you. You don’t need to do anything until your provider tells you your telephone service is changing, or until you decide to change your telephone service. It is expected that providers will have a range of options for people who don't have broadband; customers should not be forced to take out a high-speed broadband package if they do not want to.
This change will affect other devices that rely on a phone line, such as some fire and burglar alarm systems and telecare devices. So, you should mention those devices to your provider and check if these need to be replaced or reconfigured to continue working.
Unlike traditional phones, a phone connected to a broadband router will not work in a power cut, as the router gets its power from the mains. If you are dependent on your landline phone – for example, if you don’t have a mobile phone or don’t have mobile signal at your home – your provider must offer you a solution to make sure you can contact the emergency services when a power cut occurs. For example, a mobile phone (if you have signal), or a battery back-up unit for your existing phone. This is discussed on the OFCOM website using the link above.
A typical Digital Voice package (already available from some ISPs) includes
the option to retain your existing landline number, 1000 minutes monthly free to UK mobiles and landlines.
The following features are offered:
An excellent coverage of the many aspects of digital voice has been produced by CSW - the group who worked with (previous) Parish Council on broadband provision in Sambourne.