It’s no secret that I’ve been living with a couple of Polycom VVX-1500 Business Media Phones around my office for the past few months. My review of these devices will shortly run over at Small Net Builder.
This is one of the few times that 3000 words seemed like a problem. That is, I could use more space to get into more detail about the devices. Perhaps we’ll run a follow-up later on. That’d be great, presuming that I get to run a trial installation of the phones as I hope.
Anyway, Media Phones. It’s a whole new category. It’s like the iPhone for the home or office. That includes some other devices that I’ve shown interest in, like the Verizon HUB from Open Peak, and Glass from Cloud Telecomputers (pictured).
I read this item on the flight from Houston to Baltimore this morning. There’s some interesting stuff in there, both for residential and business applications. But then something caught my attention. It’s the following paragraph:
Wideband or high-definition (HD) VoIP is one of the latest innovations to hit the IP-PBX industry. The G.722 codec shrinks the voice channel bit rate to 12.65Kbps. With standard narrowband VoIP, the voice signal is sampled at 8,000 times per second, resulting in an effective voice pass-band ratio of about 200:3300Hz. The G.722 wideband codec doubles the sample rate, delivering an effective pass-band ratio of 50:7,000Hz.
I find myself wondering, “is that just a typo? Or a more serious mistake?” The G.722 codec most definitely does not compress a voice stream to 12.65 kpbs. The G.722.2 codec (aka AMR-WB) can achieve that data rate, but these are two wholly different codecs.
Then they express the useful frequency response of the audio channel as a “ratio” of 200:3300Hz. That’s just flat out wrong. It should be expressed as 200 Hz to 3300 Hz, preferably with some qualifier like +/- 3 db.
Maybe I’m just being finicky about the details. It does strike me as odd the such simple mistakes end up in a report like this. It serves to undermine the credibility of the document as a whole. Don’t you think?