Looks like @VoIPSupply figured out HD Voice over the PSTN – Website says, “…available in HD 8:30am–9pm weekdays. — Toll Free: 1-800…” 😉
That’s novel, right? The thing is that they offer only a toll free PSTN number as a contact method. Here’s a screen shot of a portion of their home page.
I expect that at present it’s very unlikely that you could actually have an HDVoice call with anyone at VoIP Supply. It’s not impossible, but unlikely.
With rare exception, to have an HDVoice call you need an IP-based call path from end-to-end. The call cannot transit the PSTN. Yet the common “phone number” is in fact an aspect of the PSTN.
I once had an HDVoice call with Rob Wolpov of Junction Networks, and it was achieved by simply dialing a common NANPA number. The only contact details I was given for the interview was a 212 area phone number. Since Rob was using a better Polycom phone, like my own IP650, and we were both registered to the same SIP registrar, the call path was pure IP and HDVoice was possible.
Beyond the serendipitous use of the same SIP service provider passing HDVoice streams relies upon IP-based peering between Telcos & ITSPs. Such peering arrangements provide the IP call path required to use wideband codecs. That’s a trend that remains in its early days, but it is growing.
As a little experiment I called VoIP Supply at the toll free number they offered on the web site. Here’s a picture of the LCD on the Polycom Soundpoint IP450 that I used to make that call.
Those of you familiar with Polycom phones will note that the little animated HD icon for extension 2040 is not being displayed. As expected, the call was not connected in HDVoice.
I wonder who VoIP Supply uses for SIP trunks? Or if they use SIP trunks at all? If that was known I might be able to work out how to reach their ITSP via SIP URI, and try to ensure an IP-based call path.
In reality this is a minor thing. It’s nice to see a large player like VoIP Supply pushing the idea of HDVoice. If you look further into their site you’ll find that they have some nice introductory information on the topic.