Wideband Audio and Softphones
It was very interesting to read Michael Graves’ “Rant” on softphones. What I found intriguing was that it seemed to be all about the need for wideband audio (and G.722). Wideband audio is defined by 16 kHZ sampling frequency (compared to 8 kHz sampling for narrowband used in regular telephony), which also doubles to audio bandwidth and provides fidelity closer to CD quality than the clunky telephony quality we are used to.
Skype is to me a softphone, and I see them as the enabler of the softphone market providing the breakthrough for desktop VoIP. The 2 major reasons for Skype’s success were that their service actually worked, and their high audio quality. They were able to raise the bar on audio quality largely because they had robust wideband audio from the get go. Codec wise, Skype has always been proprietary (proprietary vs. standards is another long story) and I think G.722 is old circuit switched technology not very well suited for packet networks.
Google Talk is in my book an even higher quality “softphone” (it seems like Google is never happy with anything but the best) and of course also wideband audio (using the GIPS iSAC codec).
Tags: codecs, Google Talk, Skype, softphones, wideband
November 25th, 2008 at 12:15 pm
As a practical matter we still require hard phones in our business. To that end we purchased some very nice Polycom hardware that supports wideband through G.722. We are very happy with these devices. So I was, and remain, seeking a soft phone that would fit into this scenario. A soft phone with G.722 support.
Perhaps in the future Polycom will expand the codec support in their hardware. That’d be a good solution, too. Soft phones with faulty/unusable G.722 implementations are not a solution at all.
There are other codecs, like iSac, that have advantages, but without support for them in commonly available hardware they don’t do me any good. I can’t make a wideband call from Skype or Gizmo5 to a Polycom IP650 or snom 370, even by direct IP connection.
Interoperability with commonly available hardware is not just a nicety. It’s essential. Witness the fact that even Skype has to deal with G.711 to terminate Skype in/out calls.
November 25th, 2008 at 2:38 pm
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November 27th, 2008 at 5:04 am
Thanks for your comment, I understand and sympathize with the need for interoperability. In fact, GIPS is open with regards to codecs and supports what customers want. We do have support for G.722, but I don’t think many are using it as you noted.
Regarding iSAC, we are working on strategies for more HW implementations. Stay tuned!
November 27th, 2008 at 5:57 am
Roar,
If you have support for G.722 in your codec library then perhaps you might suggest its use to either Gizmo5 or GoogleTalk? That would give them instant interoperability with a diverse range of hardware.