I got a new XMPP number from JMP.chat for “VOIP” and I haven’t looked back. I can call my brother in France whenever I feel like it. I think I pay $5.00 a month. It integrates with Dino and, sort of, with Chatty. I also use it in a web browser through https://movim.eu/. I installed a webapp and can message and call people very well through that Webapp with the JMP.chat number. Works darn good.
See here for more information: VOIP with jmp.chat and gajim