Hamshack Hotline
Hamshack Hotline (HH) is a FREE dedicated voip telecom service for the Ham Radio community. (taken from their website - see https://hamshackhotline.com )
I heard about this via, if I remember a post on Facebook. It sounded interesting, and free, and so I purchased a refurbished Cisco SPA504G VoIP phone from a trader on eBay. Once you register with them they send a link to a configuration file for the phone and this makes it all work. So, what do you get? Well, review the website but basically a VoIP phone and an online phone directory. The line is full featured with 'do not disturb' and an answering machine. The exchanges are set up in various places - I am connected to the European one (HHEU). There is also an exchange for unlicensed members. RF links are being set up too for those with an amateur radio licence.
As the service expands this could be a very interesting facility, and for the price of the phone - around £20 - one I could not resist.
They support a small range of SIP phones and I chose the 504G because it uses PoE, meaning no wall-wart as it gets its power via the Ethernet cable from our PoE switch.