Re: Freeh slimes again: Digital Telephony costs $2 billion now ...

[jim bell <jimbell@pacifier.com>]

At 01:11 PM 8/2/96 -0700, Lucky Green wrote:
>At 18:29 8/1/96, Timothy C. May wrote:
>
>>(With the Internet Phone deals--even Intel is entering the market--why are
>>there no widespread uses of PGP or S/MIME? Yes, I know about about PGPhone,
>>and also the Nautilus product, but none seem to be used by anyone I know.
>>Maybe we should spend some time talking about the practical realities of
>>these tools.)
>
>The sound quality really isn't there, unless you have a fast machine or a
>fat pipe. In addition, the vast majority of Intel based computers lack the
>crucial (for user acceptance) full-duplex soundcard. Add to that the
>physical impossibility of getting decent real time services over a
>non-isochronous network, such as the Internet, I'net phones just don't
>provide suffcient speech quality for business/serious personal use even
>without the added overhead of crypto.

Which reminds me...  If there is any function Cypherpunks (and/or 
cyberpunks) should perform, it's one of using a "bully pulpit" to influence 
technical developments.  Consider, for example,  your observation that "the 
vast majority of Intel based computers lack the crucual full-duplex 
soundcard."  When I first heard that this was true, I wondered what bunch 
of nincompoops were responsible for this outrage.

There are  many potential uses for soundcards which require full-duplex 
operation.  Only the most stupid and basic functions don't.  There was no 
good reason for this lack; Presumably if somebody had been at the 
right place at the right time, he could have reminded that shit-for-brains 
"engineer" of the obvious consequences of building a product with such an 
egregious bug designed into it.

Anyway, that's water under the bridge.  However, we're probably all in 
agreement that Internet telephone (non-encrypted as well as encrypted) is 
going to be a big product in just a few years. This will require (or desire) 
a few high-CPU-power functions:

1.  A modem, obviously.
2.  Good encryption, possibly.
3.  Audio A/D and D/A, and associated compression functions.

 I propose that the better way of implementing it, rather than going through 
a sound card, is for modem manufacturers to built an  new modem with an 
extra telephone connection (perhaps the same physical connector that's 
currently used for the telephone handset) which goes to an ordinary 
telephone and does the audio A/D and D/A conversion, as well as the data 
compression/data expansion function that will be necessary.  The latter 
function would be done by an extra DSP on this modem/Internet telephone card. 

 Briefly, you'd talk into an ordinary telephone on your desk, which would be 
connected to the modem/telephone card.  That card would digitize your speech 
to whatever level of resolution  is practical, and compress it into an 
appropriate data rate.  This data would either be encrypted by the same DSP, 
or possibly presented to the host CPU for encryption.  From there, it would 
be sent to the modem section and transmitted over the telephone line. 

I think this would be superior to the use of a sound card, for a number of 
reasons.  First, obviously, is the reduction in cards in simple and/or 
portable systems.  To require that you have both a modem and a sound card 
(as well as a cpu) to implement an Internet telephone is unreasonable.  
Secondly, using a sound card (which can't do any compression) requires that 
you implement both the compresssion and encryption function with the host 
processor, which might be impractical for a low-cost processor like a '486.  
Putting a substantial portion of this function into a dedicated DSP means 
that main-processor overhead becomes minimal.  

Third, implementing a "flow-through" telephone circuit allows you to 
interpose this encryptor into an existing telephone system, such as that of 
a house or office.  The existing handsets can be used with no modification, 
presumably.  This would also allow easy implementation of a 
computer-controlled answering machine-type, because the computer will be 
able to digitize/synthesize audio as well as record it.  It could also 
implement fax and modem/bbs functions.





Jim Bell
jimbell@pacifier.com