Eric Hughes wrote:
the great voice-over-data protocols and products introduced by Intel, Rockwell, ZyXEL and others at Comdex which will make Voice-PGP so much easier
As I understand these voice-over-data products, the voice goes over analog, added to the modem signal. The modem signal is interpreted, and then reconstructed and subtracted from the incoming signal, leaving voice. Very clever, but insufficient for secure phones.
I don't think that's how they do it. As far as I know, most methods multiplex digitized audio with the data. One system used by some people in India provides a dynamic combination of fax, (digitized) voice and data, depending on the throughput - eg vox/9.6 data if 14.4kbps, fax as well if 19.2, etc. While Intel and others are proposing standards, ZyXEL does it with software along with a voice card or possibly RJ11 input. A friend of mine saw a demo of it at Comdex, on an old 1496E (16.8 kbps zyxel to zyxel). The new v.34 does 28.8k - lots of room for clear digitized voice and high speed data. This is exactly why I thought it would make secure voice easier, if not secure phones (who wants to lug a modem and PC around as a 'handset'?). I'll be testing some Onetics Rad VFAST modems this week, which apparently do digitized voice over v.34 as well. ----------------------------------------------------------------------------- Rishab Aiyer Ghosh "Clean the air! clean the sky! wash the wind! rishab@dxm.ernet.in take stone from stone and wash them..." rishab@arbornet.org Voice/Fax/Data +91 11 6853410 Voicemail +91 11 3760335 H 34C Saket, New Delhi 110017, INDIA