As advertised, receiving faxes via 3CX Fax server is easy to set up and works well. We have regular SIP trunk provider, our system on the Cloud, Debian server. Setting up fax reception was easy and we have tried on fixed fax as well as web faxing service; both types work well in 3CX Fax Server. Sending faxes from PC is not mentioned in 3CX documentation (for v15.5). Prior versions, for example 12, 12.5 etc had some support from 3CX, such as recommendation of 3rd party software (GoldBolt, for example) and we tried most of those but the results were mixed so we continued using Web Fax services instead. On 3CX v 15.5 we've installed FAX Voip FSP module that is coupled with Windows Fax and Scan. We have set up an additional, regular extension (not Fax extension) and registered it with through Fax Voip FSP. We have been testing this setup for a week now and, apart from occasional hick up it is testing very well. Essentially we are going to substitute Web Fax with 3CX fax, bidirectional now, with very reasonable investment in software, good savings ahead, control back to owner. Progress? May be dependable on Net Neutrality...but we are holding our breath.