- Nuvio has you covered on conferencing. NuvioFlex offers you three ways to have conference calls. The easiest way for a two or three person conference is just to initiate the conference call from your VoIP phone or softphone. However, if you want to have more than that in your conference, NuvioFlex offers you free, yes free, conference rooms that you can use. You can utilize your existing Flex lines to have outside callers call in as well as unlimited internal users that are on the NuvioFlex. If you don't want to tie up your Flex lines, Nuvio offers a special dial in number that charges a per minute rate that is very competitive with commercial conferencing companies.