geoffw@nexsys.net (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. Bill Stewart