Comment Re:WebRTC, Asterisk/FreeSwitch and a JS SIP client (Score 2) 194
I'd simply buy proper hardware SIP phones. Polycom VVX series, Yaelink vp530pn (nice conferencing for 3 or more parties) or something made by Cisco (i haven't played with those). As long as it isn't made by Grandstream, it is practically maintenance free. You just set up a SIP server in the middle or buy the service from a third party.