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Re: "Secure Voice"
[email protected] (Geoff White) writes:
> Anybody know about the voice capabilities of the ZyXel class modems?
> I own a ZyXel 1496E which can digitize voice and also transmit
> voice data that has been digitized. It would be easy to
> first encript this stream before sending it out.
> The 1496E+ also support CELP (or is it (CLEP?) but that one
> cost about $400. (The 1496E is around $300) It also is a 14.4 K
> baud modem and does FAX.
The ZyXel has a 68xxx and a DSP chip. It's able to digitize and compress voice,
and also to play back digitized voice, and also to do 9600/14400 modeming,
but it can't do all three at once. To build a secure voice phone with Zyxels,
you'd need either 2 or 3 modems - one to handle the modem functions,
one to compress the voice, and either the same or a separate one to play voice.
But it's a good start.
What I'd like to see is a SoundBlaster followon with a DSP chip.
It IS possible to get DSP boards for PCs and I think for Macs,
so you could build a system easily enough with a DSP board and a SoundBlaster,
but the last time I checked, the DSP boards tended to be expensive
and packaged with lots of fancy waveform analysis tools.