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TELECOM Digest     Sun, 16 Jan 94 23:04:00 CST    Volume 14 : Issue 36

Inside This Issue:                          Editor: Patrick A. Townson

    Re: Unmetered Local Service (Danny Burstein)
    Re: Unmetered Local Service (Robert L. McMillin)
    Re: Shannon's Law (was Re: Hayes' New Modem) (Clarence Dold)
    Re: Shannon's Law (was Re: Hayes' New Modem) (Charles Randall Yates)
    Re: ISDN: Coming Soon to my House? (Al Varney)
    Re: SW-56 and ISDN Questions (Dave Cherkus)
    Re: Surcharge for Tone Dialing to be Dropped (A. Padgett Peterson)
    Re: Wanted: PC/Mac Voicemail Recommendations (Jonathan Reiser)
    Re: Announcing networkMCI (Atri Indiresan)
    Re: Cordless Headset Telephone (Mike D. Schomburg)
    Re: US Digital Cellular Standard (Stan Scalsky)
    Re: Hayes' New Modem (Stephen Satchell)
    Re: Network Outage in 205 NPA? (Paul Cook)

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----------------------------------------------------------------------

From: [e-mail] (danny burstein)
Subject: Re: Unmetered Local Service
Date: 16 Jan 1994 13:54:29 -0500


(lots of arguments pro and against measured service vs. flat rate deleted)

Umm, to all you folk out there, let me point out a reality of life.
The telcos are in business to do one thing and one thing only. What's
that? to provide phone service?

BZZZT. wrong answer. They are in it ... TO MAKE.MONEY.FAST. (with
apologies to David Rodes ...)

They will configure the rates in such a way as to maximize their
revenue.  Pure and simple.

Now in many cases this will also help people reduce their own costs.
For example, The Telephone Company way-back-when realized that their
'long distance' equipment sat idle after business hours, and that it
cost them a -LOT- to add capacity for that 2:15pm surge in calls, so
they put in discount rates for after hours. This helped shift some
usage away from peak daytime (which lowered their costs) AND brought in
'found' revenue by increasing the number of discretionary calls.

If the 2:15 pm load was 10% higher, then they'd need more physical
plant, and would (almost justifiably) have to raise rates as well.

OTOH, most of the incomprehensable rate plans they've implemented have
been designed solely to increase revenue, WITHOUT doing much good for
the customers. For example: Here in NYC about 15 years ago NY Tel
eliminated free directory assistance calls. Instead, tehy gave a ?50
cent? credit and offerred six free calls/month. Calls above the six
would be $0.25 each (quantity and rates approximate from memory). The
idea, they claimed, was that DA calls cost the company, and by
extension the customers (never the shareholders, by the way) money.
People who 'abused' DA would get charged and everyone else would
benefit.

Of course we've seen the credit disappear, and we've seen a complete
elimination of any free DA calls ...

I could go on and on, but the key point to keep in mind here is that
the telcos are a business, not a service, and want to enhance their
money streams. In -some- cases a general good comes of it (off peak
pricing) but in most cases the only benefit is to the company. (or
should that be The Company).


[e-mail] (or [e-mail])
        (10288) 0-700-864-3242

------------------------------

Date: Sun, 16 Jan 94 16:14 PST
From: [e-mail] (Robert L. McMillin)
Subject: Re: Unmetered Local Service


On 14 Jan 1994 23:00:23 GMT, Pat wrote:

> [TELECOM Digest Editor's Note: The thing Jack Decker and other pro-
> ponents of flat rate billing seem to forget or ignore is that in most
> instances of measured billing, the majority of telephone subscribers
> actually pay LESS for service than with flat rate.

[deletia declaring modem users a small minority who will get squeezed by
per-minute rates]

But the question in my mind is this: is it *really* the case that
modem users are that small of a minority that they wouldn't be able to
resist this sort of thing?  It's happened slowly and quietly, but
there are a *lot* of homes with personal computers in them.  A goodly
number, and I would bet a majority, have modems.

In California, digital data service is coming in the guise of ISDN, or
SDS as Pac*Bell insists on calling it.  This digital service will not
carry the 500 channels of one-way television that the cable companies
and the telcos want to believe will drive their stillborn idea of the
Data Superhighway; but rather, it, and its successors, will spark a
far superior way of communication: e-mail, digital voice-mail, and
tons of other digital services.  In other words, the Data Superhighway
will be a many-to-many network of peers, not a one-to-many broadcast
network for The War Channel, Duck Hunting Network, and Macramevision
(although this isn't entirely beyond the pale).  By some estimates, as
much as 50% of the existing traffic on the telco networks is data.

If digital services are offered at reasonable prices and terms, there
is absolutely no doubt that they can spur a *real* revolution in
communications.  Obviously, for Pac*Bell to offer ISDN now seems to me
to say that they think there's enough people out there with modems who
want this service that they'll succeed.  I think they're right.

------------------------------

From: [e-mail] (Clarence Dold)
Subject: Re: Shannon's Law (was Re: Hayes' New Modem)
Organization: a2i network
Date: Mon, 17 Jan 1994 01:34:56 GMT


Of course, in the good old days, of printing _checks_ on a serial
printer, hanging off a terminal, you would always overstrike the
dollar amounts.  That way, if there was a glitch, the number would
appear bad.  A good number would appear bolded.


Clarence A Dold - [e-mail]
                - Milpitas (near San Jose) & Napa CA.

------------------------------

From: [e-mail] (Charles Randall Yates)
Subject: Re: Shannon's Law (was Re: Hayes' New Modem)
Date: 16 Jan 1994 05:57:08 GMT
Organization: University of South Florida


In article <[e-mail]> [e-mail] (Jakob Hummes)
writes:

> In article <[e-mail]>, [e-mail]2.
> dec.com (Fred R. Goldstein) writes:

>> In article <[e-mail]> [e-mail] (Jakob
>> Hummes) writes:

>>> ...But there is an absolute limit (Shannon's Law).  The
>>> question was about the transmission over a *real* phone line. And that
>>> means there exists *noise*.  The limit of bps is proportional to the
>>> logarithm of the signal to noise ratio. Unfortunately I don't remember
>>> the constant factors.

>> Shannon's law is, in plaintext,
>>      BPS(max) = Bw * log(2)((1+S)/N)

>> That is, take the signal-to-noise ration (adding 1 to signal, so a
>> negative SNR has some information present) and represent it as a power
>> of 2.  Multiply by bandwidth (in Hz) and you get BPS.

> Of course, not!
> But now I remember Shannon's Law (you have placed wrong the brackets):

>       BPS(max) = Bw * log(2)(1+(S/N))

> The addition of 1 is needed to unable a negative BPS-rate, which would
> be nonsense.

> [TELECOM Digest Editor's Note: And of course Murphy's Law says that
> when you are attempting to copy something down in plain ASCII text
> for transmission to a computer network you'll always get some one
> or more parts of it bass-ackwards to confound the readers even more
> than they are already. That error might have been Goldstein's or it
> might have been mine.  Regrets extended. Your editor, Murphy.]

I'm the one who originally posted this question, for those who don't
know. It's nice to know what Shannon's law says -- if you assume a 30
dB SNR and 3100 Hz bandwidth, the law above works out to about 31
kilobits per second. If you happened to get a quiet channel, say, 40
dB SNR, the equation returns about 41.2 kilobits per second. However,
this is still quite a ways off from a full-duplex, 28.8 kbps link, or
57.6 kbps total transfer rate. So my question still stands: How do
they do it? Are they assuming a particularly quiet channel? Are they
assuming more than the standard 3100 Hz of bandwidth is available?


Randy Yates   <[e-mail]>

------------------------------

Date: Sun, 16 Jan 94 15:58:18 CST
From: [e-mail]
Subject: Re: ISDN: Coming Soon to my House?
Organization: AT&T Network Systems


In article <[e-mail]> [e-mail] (Rob
Knauerhase) writes:

> After talking to five different people in the local GTE residential
> and business sales offices (favorite quote: "What is ISDN?", from two
> people in residential sales), I finally found someone willing to admit
> that they could sell me ISDN service.  Interestingly enough, their
> price was $48/month for 2B+D, which would provide two voice lines and
> two phone numbers.  This is about the same price as two unmeasured
> POTS lines -- what a deal.

   Actually not too bad -- but you have to get over the assumption
that ISDN is ONLY for medium-speed digital data traffic.  What's the
price for just one phone number, able to complete to each B-channel?

> Of course, this is GTE.  There has to be a catch.  For data, they
> charge the same as measured-by-minute local calls.  I asked if that
> mightn't be perhaps the silliest way to bill it (data calls by the
> minute), when a major benefit of digital telephony is that when I'm
> not using it, I'm _not using it_! (mostly)

   Sorry, but when you use ISDN to place a B-channel data (non-packet)
call, you have a data path reserved through the network for your call,
just as in the case of a voice/modem/FAX call.  At least as much
equipment is needed for such a call as for a voice call.  Sometimes
supporting ISDN data requires equipment replacement or updates, adding
to the costs of ISDN.

> That of course didn't phase them.  Even at pennies/minute, the
> advantage of faster speed is removed by cost when I can do plain-ol'
> 14.4K with compression for "free."  Is _anyone_ bothering to campaign
> phone companies and Public Utilities Commissions so that we can get
> this tarriffed in a reasonable manner (at least in places other than
> Oregon)?

   Some consumer groups will support the retention of flat-rate voice
calls in various areas.  I know of none that advocate the funding of
ISDN deployment by placing those costs into the general rate base
(forcing all telephone users to fund ISDN "free" data calls).  And if
cost recovery is only from ISDN fixed charges, very few customers will
want ISDN.  Who do you want to fund your "free" data calls.

> [Side note for those keeping score: US West in Portland offers 2B+D
> for $90/month, no limit on data.  Of course, you can't make an ISDN
> data call between GTE and US West just yet, but they're working on
> it.]

   This is difficult to believe (but possible) that such data calls
cannot be placed, since most US West and GTE areas support Switched 56
calls.  ISDN B-channel data calls rate-adapted to 56Kbps are almost
identical to and interwork well with Switched 56 calls.  The Switched
56 dialing plan usually uses '#56' as prefix digits to let the CO know
you aren't making a voice call -- with ISDN, this information in in
the SETUP message from the customer's ISDN equipment.  The interworking
also allows 56K calls from ISDN customers to reach other countries that
do not yet have ISDN in place.


Al Varney

------------------------------

From: [e-mail] (Dave Cherkus)
Subject: Re: SW-56 and ISDN Questions
Organization: UniMaster, Inc.
Date: Sun, 16 Jan 1994 19:37:34 GMT
Reply-To: [e-mail]


> 2. Here in the US what cities have been converted to ISDN, and who are
> still operating at SW-56?

You can get this info on-line from the Combinet BBS:

By popular demand, the Combinet "BBS" providing information on ISDN
availability in many areas of the US is now available via the
Internet.  The information is supplied by Bell Communications Research
and various Operating Companies and is updated periodically as new
information becomes available.

To access the service, telnet to bbs.combinet.com and login as isdn
(no password is required).  After entering an area code and
three-digit prefix, the service displays the availability of ISDN.
Also displayed is information about carrier installation prices and
monthly charges.

For those without direct Internet access, the service continues to be
available on a dialup basis using a 2400 bit/sec modem at [phone].


Dave Cherkus          UniMaster, Inc.         [e-mail]

------------------------------

Date: Sun, 16 Jan 94 08:53:13 -0500
From: [e-mail] (A. Padgett Peterson)
Subject: Re: Surcharge for Tone Dialing to be Dropped


From: [e-mail] (Dave O'Shea)

I wrote:

>> This is the scary part simce everywhere I go I see regional carriers
>> attempting to eliminate "flat" and "unmetered" plans. As telecommuting
>> and information hightway access begins to take hold, the elimination
>> of unmetered local service is the biggest threat to individual
>> connectivity that I can imagine.

> Well, in a word, no.

> If an employee is worth telecommuting, even a $4/hour connection
> charge is fairly minor in the face of, say, a $65,000 salary/benefits
> package. Even if you get charged that for eight hours a day, it's minor.

Check the math -- a typical eight-hour-a-day work-year is 2000 hours.
$4.00.hr would be U$8,000.00. Since the U$65k S+B package you mention
really works out to about $35-$40k/year take home for a family, this
would be 20-25% or about the same as a typical house payment.

Besides, it is not the highest paid employees who would be the best
candidates nor the largest group, it would be the lower level clerks,
secretaries, accounts receivables, accounts payable, etc. employees
who would make up the largest and best group.

For example, it would not particularly benefit me (though I do a lot
of things work-related from home) since it it usually the obscure
things that require hands-on that I do. It would not be practical for
me to have a full laboratory at home (though some say that I do
already), however for someone who does all of their work with a
terminal and a telephone already, it is very viable.

> Most employees who would best benefit from telecommuting are the ones
> who are well into long-distance calling areas.

Disagree here also. Metro commuting is what takes the most time and
LATAs are getting very big. I live 23 miles one way from my desk and
it is a local phone call. Metro commuting is also what takes the most
fuel and creates the most congestion.

> And who knows -- I don't follow ISDN or related services too closely,
> but it (and similar services) will become more widely available as the
> cost of bandwidth falls.

Don't hold your breath. Orlando is often touted as one of the cities
with ISDN available, but the last I looked it was confined to a very
small area that was not at either my workplace (10,000 employees) nor
my home.


Warmly,

Padgett

------------------------------

From: [e-mail] (Jonathan Reiser)
Subject: Re: Wanted: PC/Mac Voicemail Recommendations
Date: 16 Jan 1994 09:31:40 -0500
Organization: PANIX Public Access Internet and Unix, NYC


In <[e-mail]>
[e-mail] writes:

> We are building a low-cost PC or Mac-based voicemail announcement system
> (1-4 line) from existing hardware and would like recommendations on
> software and hardware.

> Please advise directly by e-mail.  Thank you!

Prometheus' fax modem/voice mail software is pretty poor, and their
technical support is even worse ... I had to jump thru hoops to get an
answer to my question:

"Why is it that I can't send faxes to my computer when my voice mail
system is running?"

The answer: Prometheus' software, when it is running the voice mail
mode, cannot recognize the tones from certain fax machines ... if
you're not going to be sending faxes to the computer, you might want
to take a chance, but I just want you to be aware of that limitation.

Note: I last tried this about eight months ago, maybe Prometheus has
come up with something different or better.

Regards and good luck,

Guppy

------------------------------

Subject: Re: Announcing networkMCI
Date: Sun, 16 Jan 1994 11:53:33 -0500
From: Atri Indiresan <[e-mail]>


Paul R. Coen <[e-mail]> wrote:

>> Is that what the MCI TV commercials with the little girl with
>> the pseudo-[B]ritish accent standing in a puddle spouting
>> existential gibberish are all about?

> Is it a girl?  I thought it was a boy.  Then again, I didn't
> look very closely.  All I noticed was an overly-perfect child
> dressed in weird black clothes and a really ghastly hat.  And
> the kid sounded like one of the brats from _Mary Poppins_.

It was a girl -- the scene (and perhaps the actress?) were taken from
the movie "The Piano". She is (or is suppposed to be) British. The
scene is in New Zealand, around the turn of the century, and she just
got off a boat from England, which would explain the clothes. While
this says nothing about NetworkMCI, I do recommend the movie.


Atri

------------------------------

Date: Sun, 16 Jan 94 09:43:54 CST
From: [e-mail] (Mike D. Schomburg)
Subject: Re: Cordless Headset Telephone


Concerning the recent request for information on cordless headset
telephones, I have been searching for items like this ever since
supervising a telco "trouble" bureau several years ago. The
technicians would have to answer service calls at desks, and then
usually walk to our nearby equipment room to perform tests. It seemed
to me that a hands-free telephone would have a dramatic effect on
productivity, but I never found the right phone for the job.

A few months ago I saw an advertisement for a thing called the Ear
Phone, made by Jabra Communications Corporation (I have no
relationship with them) which is a small device that fits in your ear
(like ear-bud headphones) and functions as both microphone AND
headset. It can plug into a regular telephone headset jack, a personal
computer (for voice control or annotation) or a CELLULAR PHONE.

I haven't tried it out, but this sounds like a really cool
application. The cellular phone has to have a special jack, but I am
guessing this will become common (the jack). Once you've got a
portable phone, who wants to use up one hand holding the dumb thing?


Mike Schomburg     [e-mail]    Lincoln Telephone

------------------------------

From: [e-mail] (Stan Scalsky)
Subject: Re: US Digital Cellular Standard
Organization: NSWC DL
Date: Sun, 16 Jan 1994 17:21:51 GMT


With all this talk about cellular standards is there anywhere to get
copies of the standards? Does the cellular industry have a location
for standards dissemination? Docs on N-AMPS/AMPS, TACS, or ETACS would
be of interest.


Thanks,

stan     [e-mail]

------------------------------

From: [e-mail]
Subject: Re: Hayes' New Modem
Date: 16 Jan 94 17:11:28 GMT
Organization: Delphi Internet Services Corporation


[e-mail] (Fred R. Goldstein) writes:

> It was often said that a phone line couldn't go beyond 26000 bps or
> so, based on the typical bandwidth and SNR.  Today a good clean line
> is more likely to be digitally switched at 64000 bps, which is well
> above the Shannon limit (digitization is lossy), but you still get a
> theoretical limit closer to 40 kbps.  Thus V.34, at 28.8 kbps, is
> pushing the envelope, but still possible.  But it won't work on a line
> that's transcoded down to 32 kbps, or just plain noisy.  Note the 300
> to 3400 Hz nominal frequency range; the 3400 is a hard filter.

The anti-aliasing filters used to be at 3400, particularly when they
were implemented using passive-filter technology.  Today, the modern
line cards are using digital filtering or active filtering (using
op-amps) and the anti-aliasing filters start having their effect at
3700 Hz.  Draft Recommendation V.34 makes used of the extended
bandwidth when available in selecting the symbol rate to use on a
connection.

The added benefit of shifting to a higher symbol rate ("baud" rate to
you old-timers) is that the Draft-V.34 modems can try to avoid a
low-frequency distortion problem caused by the transformers on certain
line cards without having to shift down in speed.

When looking at the Shannon limit, you have to look at more than just
added noise in the channl.  There is also noise caused by
intermodulation distortion which seems to be nigh near impossible to
remove from the network.

The "rule of thumb" is that the quantization noise of a companded
telephone channel is equivalent to 39 dB SNR for a single PCM channel,
36 dB SNR for two tandem (unsynchronized -- don't ask) PCM channels,
and 34 dB SNR for three tandem PCM channels.  Digital speech
compression just adds to this, although I don't have number for it
all.


Stephen Satchell, Principal
Satchell Evaluations, Incline Village, Nevada, USA
Testing modems for magazines since 1984

------------------------------

Date: Sun, 16 Jan 94 13:14 EST
From: Proctor & Associates <[e-mail]>
Subject: Re: Network Outage in 205 NPA?


I wrote:

> Anyone know what happened with the telephone network in Alabama on
> Monday?  I got a call from a customer in Arab, and I get an
> all-circuits-busy when trying to return his call on all AT&T, Sprint
> and MCI.  Did BellSouth lose a tandem switch?

Oops.  This turned out to be a local problem in GTE's switch here in
Redmond.  For some reason all of 205 was blocked from the local CO for
at least two days.  This is the same switch that serves the area that
Microsoft's main campus is in, although I am sure they have some
direct connection to their long distance carriers, so they probably
weren't affected.


Paul Cook                         206-881-7000
Proctor & Associates         MCI Mail 399-1080
15050 NE 36th St.            fax: [phone]
Redmond, WA  98052-5378    [e-mail]

------------------------------

End of TELECOM Digest V14 #36
*****************************