This was the first VoIP provider I tried, and I liked quite a few things about them. I really wanted this to work out, but in the end there was one single showstopper that led me to switch to PhonePower.
VOIPo's residential service has quite a few bells and whistles that I found useful. One key feature is the way they allow you to forward calls to your cell phone(s) for simultaneous rings. Normally this is an issue because your cell phone's voicemail might pick up the call (right away if you have no coverage), and your home phone will stop ringing. With VOIPo, once you pick up a forwarded call, you need to confirm that you want to receive it... A very simple and practical safeguard that I wish PhonePower had as well.
Also, it allows you to pick any of your registered numbers (virtual numbers, your cell phone numbers) as outgoing Caller ID. In my case, I have no cell phone coverage at home, so this allows me to use my cell phone number as my public "main" presence regardless. Combined with forwarding unanswered calls from my cell phone to my VOIPo number, I can then pick up incoming calls whether I'm in coverage (my cell), at home, or via a SIP soft phone from anywhere. (What particularly makes this attractive is that VOIPo's voice mail system is nicer and more practical than that of my cell phone carrier... voice mails can be sent to your email address as attachments, for instance).
Now the negatives.
First, the VOIPo-supplied phone adapter would lose its registration at regular intervals. My home network is behind a NAT router (basically a Linux box with masquerading firewall, but it's apparently the same issue with a standard NAT/broadband router you'd buy in a store), which means that the adapter does not have a public IP address (presence) on the Internet. So the adapter can initiate contact with the VOIP registration server, but not the other way around.
To keep the channel open, the device would normally send "keep-alive" packets to the server at regular intervals.. say every 30 seconds or so. Also, the device needs to re-register with the service every so often - perhaps every 1 - 3 hours.
For whatever reason, the VOIPo Registration server keeps losing the VOIPo adapter's registration after a few (10-15) minutes, and the device would not be able to receive incoming call until its next registration, some 45 minutes later. In other words, it would have an active "duty cycle", as it were, of some 1/4 of the time.
I did some testing, using my own VoIP soft phone (a Yealink SIP-22P from Amazon), and found a similar issue - at the default 3600 second/1 hour registration interval (even with keep-alive packets every 30 seconds in the interim), the VOIPo registration would lapse after 10-15 minutes. To work around this, I had to set the registration interval very short - 300 seconds/5 minutes. After this, I did not have any more registration issues with my SIP phone (or my soft phones) - but since I was not able to configure the VOIPo adapter, I was not able to use this. [*][**]
[*] VOIPo included a piece of paper with the adapter where they explained that if you are behind a NAT router, you need to forward all incoming traffic on UDP ports 2000-65000 to their adapter. This is a non-starter if you, like me, have other services in use. Also even when testing this, it did not seem to address the problem.
[**] In contrast, I now use a 7200 second (2 hour) registration interval with PhonePower, without any issues whatsoever. It's simply rock solid.
This led me straight to the 2nd and more important showstopper. International calls are restricted when using your own device (like my SIP phone). You can whitelist specific countries, but this does not always work. I had to contact their tech support line for them to fix something in order to be able to call to Norway, and even after multiple attempts, they were unable to fix whitelisting of calls to Taiwan.
In other words:
- Calling certain destinations is only possible when using the VOIPo supplied adapter
- The VOIPo supplied adapter does not work well behind NAT firewalls.
Lastly, although voice quality was overall pretty good - VERY good at times - there were other times when the voice was terribly garbled both ways. I've not experienced this once I switched to PhonePower.