The options are cool but the call quality is iffy, I tried it but I'm wierd about echoes in phone conversations so I couldn't deal with voip...
Those are typically hardware configuration issues, and should been sorted out by the company providing service. All your cell phone traffic today is basically VoIP, but few complain about quality. Cause the big telco's control the network traffic end to end.
Beside the cool PBX options and nifty phone routing features, the biggest advantage to VoIP is audio compression. A plain old telephone line or POTS uses roughly 64kbps of bandwidth. VoIP codecs options range from G.711 (64kbps) to G.723 (5kbps) with G.729 (8kbps) providing best bang for buck and my personal favorite in quality. Good description of the Codec options in link below.
https://www.cisco.com/c/en/us/support/docs/voice/voice-quality/7934-bwidth-consume.html
In the telcom world a hardwired T1 circuit contains 24 POTS @ 64kbps or 1544 kbps total bandwidth. If that T1 is IP configured to run only data no analog, then 1.5mbps can support max of 24 VoIP calls at G.711, or 300 VoIP calls running a 5kbps G.723 codec.
However G.723 is about one notch above a walki-talki.. For the service providers it's a money maker shooting traffic into 3rd world countries over satellite links for example. However not what our ears are accustom to, and can't even support a FAX machine.
Reason I bring all this up, these Codec are setup in your phones, and must match up to the IPBX on far end. It's a handshake arrangement where the PBX says I'd like to use G.723 and you phone can reply, "sorry I only accept G.729 or G.711 so pick one of those."
G.711 will always provide your best call quality, unless your kids hosting a gaming party on PS4, wife streaming Netflix, and your 15yr old DSL router is compromised by some hacker now using it to mine bitcoin in the background. Then ya end up hearing "
Max Headroom" talking to ya during that important business call...
So it takes a bit of IT knowledge on the business end to make VoIP sound like a POTS all the time. But once ya verify internet bandwidth is good, use a decent router with QOS ability to set VoIP as priority over all other network traffic, you'll totally forget it's not a POTS line.
And BTW,, please support Net Neutrality through
EFF NOW!! because if your big ISP's / ATT gets their way, all this current "end user" QOS ability goes out the window, and they can control / prioritize your IP packets by who pays them most $$$. Then all these little VoIP companies gonna get trashed when their call quality drops off because Netflix pays better, and ATT want's to sell you VoIP service ... The 20yrs break I took from turning wrenches, was spent developing all this stuff above, 8yrs for said ISP ^^....