Losing power at your premises can cause your Internet connection to go down. If this happens you will not be able to make calls unless you are equipped with a backup UPS which could power the connection for a limited short duration. Using a UPS to power your network equipment including phones should allow an Internet connection to be maintained for a short duration and should suffice for short local outages, providing that your ISP is still powered up from your connection to their head end. IT.ie can divert calls to mobiles in the eventuality of any failure.