TELECOM Digest     Tue, 7 Feb 95 01:29:00 CST    Volume 15 : Issue 82

Inside This Issue:                         Editor: Patrick A. Townson

    Re: LD Termination Fees to RBOCs (Fred R. Goldstein)
    Re: Cellular Fraud: How Much of it is Real Money? (Michael D. 
Sullivan)
    Re: What is a T1 Line? (Al Varney)
    Re: Cheap Way to Get an 800 Number? (Paul Robinson)
    Re: 28.8k bps Modem (Paul Robinson)
    New Archives Email Service Feature (TELECOM Digest Editor)

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

From: fgoldstein@bbn.com (Fred R. Goldstein)
Subject: Re: LD Termination Fees to RBOCs
Date: Mon, 6 Feb 1995 14:47:44 GMT
Organization: Bolt Beranek & Newman Inc.


In article <telecom15.77.10@eecs.nwu.edu> rta <75462.3552@compuserve.
com> writes:

> Several issues are being raised here so let me try to sort them out.
> For FGD, many tariffs if you break them down, have a 1/3 the cost in
> switching, paying for COs and access tandems, 1/3 in transport, the
> bandwidth, and 1/3 in Common Carrier Line on the originating or
> terminating end, what the carrier pays to support (subsidize) the 
line
> to your home or business. This breakdown is approximate and varies
> from LEC to LEC, but it gives you the overall picture.  Only about a
> third of the charge is for bandwidth as most of us would interpret 
the
> word. The other element is switching.

That happens to be the way Feature Group trunks are priced.  Of course
the whole trick to FG pricing is that it's intended to be 
"contributory" 
(profitable).  This comes from the old separations game of "splifs",
for "subscriber plant factor" (SPF).  In that game, the average usage
of LOCAL lines is divided into interstate and intrastate baskets.  The
interstate portion is MULTIPLIED by SPF and then the total cost is
divided amongst the two jurisictions.  Given SPF of 3 (old ballpark; I
don't know what it is now), then if 15% of calls in a jurisdiction
were interstate, then the cost would be divided 85:45 to 
local/interstate.  
The subsidy, folks, is in the splifs.

Interstate cost is currently divided into the part paid via tolls and
the part paid via CALC ($3-6/mo "access charges").  The toll-usage
part is divided into different components and adds up to 3-5c/minute/
side-of-call for most telcos.

> Switching and the lines to the customer premises are really what is
> expensive.  The lines are not heavily utilized, in the case of many
> small businesses and residences. Switches are expensive and are not
> set up to support multiple hour calls.  Regular business calls that
> get through are typically 4 to 6 minutes in length with residential
> calls longer since many are placed to friends and family. Switches
> were engineered on the assumption that most calls would be short. As
> data usage increases, the switches have to get bigger, an expensive
> proposition or the multiple hour data calls will have to shifted to
> another technology, such as packet or cell switching where switches
> and long distance circuits are not tied up during think time.

Strowger switch costs were heavily usage-oriented.  Modern switch
costs have a minor usage component, less than .1c/minute if you
compute it, for local calls.  Data usage could "pay its own way" at a
fraction of a cent/minute for local calls.  Don't let the phone
companies fool you otherwise.

> Most modern CO switches detect a phone that is off the hook and not
> transmitting and generate an obnoxious tone to get you to hang up.

Proof that somebody's trying to confuse the issue.  The howler tone
does not tie up major resources in a modern switch; the line card is
just connected to a tone generator channel.  On an old Strowger it
could hang a line finder.

> Jerry Harder   Senior Partner
> Renaissance Telecommunications Associates

Lemme guess.  A consulting firm specializing in helping telcos win 
rate 
hikes?


Fred R. Goldstein   k1io    fgoldstein@bbn.com
Bolt Beranek & Newman Inc., Cambridge MA  USA   +1 617 873 3850

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

From: mds@access.digex.net (Michael D. Sullivan)
Subject: Re: Cellular Fraud: How Much of it is Real Money?
Date: 6 Feb 1995 03:50:31 -0500
Organization: Wilkinson, Barker, Knauer & Quinn (Washington, DC, USA)


bruce@zuhause.MN.ORG (Bruce Albrecht) writes:

> My question is that if they are truly losing hundreds of millions of
> dollars a year to fraud, why aren't they switching to known 
technologies 
> (e.g., GSM based) which have per call authentication using a random
> number query with an encrypted key response, when such systems have
> been available for several years in other parts of the world?  If 
they
> really are losing $300 million or more a year, it must be cheaper to
> replace every single cellular phone with a more secure system than 
to
> let these losses continue to escalate.

At least in part because the FCC *requires* all cellular carriers to
provide AMPS-standard, unencrypted, analog service.  They are free to
offer alternatives as well, such as CDMA and TDMA (GSM, too, if anyone
cared to do so), but they still have to provide service to unencrypted
analog customers.

Also, phones using the unencrypted AMPS standard are cheaper and
provide better voice quality than the alternatives; the companies'
customers have analog phones.  Cutting off the majority of your
customers to prevent fraud is a great way to go out of business.

The cellular manufacturers have been working on new standards for
nearly ten years.  They aren't about to come up with yet another
standard -- analog with encryption -- that will be incompatible with
every system out there, and the carriers aren't about to buy it when
they plan to transition to digital over time and do away with analog
when the FCC allows it and their customers accept it.  PCS, on the
other hand, has the advantage of reinventing the wheel, since there's
no embedded base of equipment.  Unfortunately, there are something
like seven different standards under consideration for PCS (including
at least one GSM variant).

> If most of this amount is funny money, "lost profits" that they 
never
> really expected to generate, and use of excess capacity, then are 
the
> phone companies crying wolf?  Are we currently in the position where
> the phone companies are like the suburban/rural household that never
> locks their doors "because crime never used to be a problem", and 
now
> screams for more police because they keep getting burglarized, but
> still never lock their doors?

The carriers have tried a lot of things, from "electronic signatures"
of phones that have to match a database entry to PIN numbers etc.  The
latest is the FCC's new rule, which the manufacturers hate, that
requires the ESN to be unchangeable, period.  This, unfortunately, is
kind of like making it illegal to build a house without locks to
prevent burglary.

> My main concern over cellular telephone fraud is that because it is
> partly due to decisions made by the phone companies, and that it's
> probably been exaggerated, that our government is either going to
> respond with excessive legislative and/or regulatory reaction to a
> technical problem, or with no action at all.  Either way, it sends 
the
> wrong message.

As discussed above, it's not just decisions made by the phone
companies; it's decisions made by the government, purchases made by
consumers, and the limits of technology.  Are we going to eliminate
credit card fraud by eliminating account numbers or mag stripes and
require voiceprints?  No.  Are we going to eliminate software piracy
by reqiring copy protection?  No.  Similarly, we can't eliminate
cellular fraud by requiring use of a standard that obsoletes all of
the existing phones and cellular systems.


Michael D. Sullivan | INTERNET E-MAIL TO:  mds@access.digex.net   
Bethesda, Md., USA  | also avogadro@well.com, 
74160.1134@compuserve.com

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

From: varney@usgp4.ih.att.com (Al Varney)
Subject: Re: What is a T1 Line?
Organization: AT&T Network Systems
Date: Mon, 6 Feb 1995 08:54:21 GMT


In article <telecom15.42.10@eecs.nwu.edu>, Butch lcroan/.nameBalcroan
Lilli <balcroan@netcom.com> wrote:

> ARGHHH !! I am really getting tired of this BIT-Robbing conversation
> that Jeffery Rhodes started. I used to work with Jeffery and he
> certainly is a smart guy, but he is no expert in this area.

> ... but there is more to consider here. The " MU LAW " is not a 
linear
> scale it is more of a log function with more steps closer to the 
lower
> levels where the ear is more senstive. I really can't believe 2 DB;
> come on Jeff, 3 db is half power *and also the least amount the ear 
can 
> detect*.

   Jeff certainly can fend for himself in this forum, so this is just
to add a little FACT to the fray.  Butch, you were right -- Jeff was
stretching the truth.  The actual drop in Signal-to-Distortion ratio
with 1/6 bit robbing between two switches is 1.8 dB, not 2.  Of
course, when there are 5 switches in the connection, the ratio drops
by up to 4.2 dB.  (5 out of 6 bits are affected on 10% of the calls,
4/6 on 40%, 3/6 on 40%, 2/6 on 10% and 1/6 less than 1%.)

   On a typical mid-length call (intraLATA toll or between adjacent
LATAs), 3 out of 6 bits will be robbed 57% of the time and the ratio
drops by about 3.2 dB.

> I really doubt that the modems are affected by this as
> much as Jeffery has stated. I would more believe than something more
> common such as " ECHO " and several other more common impairments 
are
> really alot more important than a occasional bit robbing.

   I agree that S/D ratio is not a BIG issue with modems, but it does
place a small per-call variation into the connection -- and that could
be just enough (combined with echo/cross-talk) to force a modem to
back-off to a lower transmission rate.  It is probably at least as
much of a factor as the individual variation between two different
modem lines at a common location.

> There are also several new technologies such as fiber that have
> introduced timing impairments such as " Jitter " into the equation.

   Jitter exists on all synchronous transport mechanisms, even ISDN
lines.  Copper-based, fiber-based, microwave-based, soliton-based all
jitter.  Whether it is a significant problem usually depends at least
partly on the bit-rate, repeater design and bit-detection mechanisms.
You seem to have it in for optical-based media -- what do you have
against photons?


Al Varney

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

Date: Mon, 06 Feb 1995 10:11:14 EST 
From: Paul Robinson <paul@tdr.com>
Organization: Tansin A. Darcos & Company, Silver Spring, MD USA
Subject: Re: Cheap Way to Get an 800 Number?


> Some friends and I are starting a new small business. We would like 
to
> have an 800 number. How do I get one? 

You call a long distance carrier's 800 number and tell them you want
one.  Within a couple of business days they will turn on the number.

> Other than ATT/MCI/Sprint, are there other people who can provide an 
> 800 number cheaply? 

Don't know how much you mean by 'cheaply'. My 800 number from AT&T
costs me $8 a month plus usage, which is typically around 20-25c a
minute depending on how far the person is from Maryland.  As I
typically have a low calling volume, the costs usually run only $12 a
month or so.

> How do I minimize my cost?

First you have to figure how many calls you expect to receive.  If you
are doing a substantial number of calls now, you might see some of
them move to the 800 number.  If you see you are getting large volumes
of calls, you can change your service to a different plan which
charges slightly more for the service and less per minute.

> How do I get 800-CALL-MY-BUSINESS? Do I have have to pay extra for a
> "good" 800 number.

I originally had Sprint for my 800 number.  The number I wanted --
since my company name is "Tansin A Darcos & Company" -- the number I
wanted to get was 1-800-TDARCOS.  I couldn't get it; it was apparently
reserved by someone else, even though calling it indicated that the
number said it wasn't in service.

The business line here is 301-587-6354.  So, I got *that* number from
Sprint, e.g. 1-800-587-6354 which is a nice idea.  I checked later
with AT&T when I saw their rate was fairly competitive with Sprint.
Guess what: AT&T *was* able to give me 1-800-832-7267 (800-TDARCOS).
So I moved to them.

There was one item that I was not told, which suggest you ask all
costs in advance.  Sprint enabled the number I asked for -- the one
that matched my telephone number -- for the fee of something like $10
a month, and included a listing with 800-555-1212 and even allowed
calls from Canada; they asked me if I wanted to allow that, I said ok.

When AT&T turned on the new number, there was an additional 
"installation" 
charge of $45.  

During a one month period, both 800 numbers from each carrier 
terminated 
on the same 301-587-6354 number so, unless a carrier has some rules
against it, you can have multiple numbers terminating on the same 
line.

Also, there is no longer an instate/out of state restriction.  I can 
call 
my 800 number from another phone in the same room, or I can call it 
from 
Virginia (which is out of state but also a local call in this area).  
You
no longer have to have separate instate/out of state numbers.  And my 
bill 
shows the ANI of every call I've received, which occasionally includes 
calls 
 from places like Texas or New York.

Another thing to consider is who had your 800 number before; if it was
in use by someone else recently.

I used to have a big problem with my old 800 number I had a couple of
years ago (this was before you could ask for a specific number); the
former owner was a freight broker, so I got calls from long hall
truckers across the country telling me about partially empty trucks
available from point a to point b.  I finally had to put an 
announcement 
on the line that said "Tansin A. Darcos & Company, a computer software
development company."

This is a point that is probably going to be a problem for the local
telephone companies.  Bell Atlantic will sell an 800 number for
instate calls (it mentions this in the phone book); because of the
long distance restriction they cannot provide interstate delivery.  I
doubt they can be much cheaper than a national carrier; if I can get
an 800 number from Sprint for $10 a month that allows me to receive
calls from anywhere in the US or Canada, why would I want a number
that only works in my home state?

About the only reason I could see is if you wanted a restriction on
incoming calls from this state.  But that's a problem too: within a 50
mile radius of where I am includes in MD: Baltimore, BWI Airport, all
of Montgomery and Prince George's county, the state capital at 
Anapolis, 
parts of Howard County, but it also includes interstate areas 
including 
all of Washington, DC, Independent Cities of Alexandria, Falls Church,
and Fairfax, Va; towns of Vienna and Manassas, plus Fairfax and 
Arlington 
Counties in VA, plus Washington National and Dulles Airports. If I
want to reach anyone I can get to in a two-hour radius, an in-state
only 800 number is worthless.  In fact, most companies operating
anywhere within twenty miles of Washington typically will operate in
DC plus the cities and counties in both states surrounding it.

For example, a large local plumber here lists one number to call in
the greater Washington area: 1-800-4-HOT-WATER.  I know they are
licensed in all three jurisdictions.  While they could probably take
calls from Baltimore, or Arlington, VA, calls to them from, say,
Dallas/Ft Worth or Los Angeles or Chicago would be worthless.  Yet
since they don't advertise there, paying more per month to block calls
outside the local area probably isn't worth the extra cost, e.g if you
get $3 worth of wrong numbers a month, paying an extra $20 to restrict
area codes you don't want to service is not cost effective.

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

Date: Mon, 06 Feb 1995 10:54:58 EST 
From: Paul Robinson <paul@tdr.com>
Organization: Tansin A. Darcos & Company, Silver Spring, MD USA
Subject: Re: 28.8k bps Modem


Victor Hu <vhu@AGSM.UCLA.EDU>, writes:

> I just purchased a 28.8 K modem with the brand "Supra".  I paid 
extra 
> to get the 28.8 K instead of the 14.4 K.

Probably about twice as much. 14K modems are down to $50 or so. 28Ks
are probably in the $100 range.  I purchased a 14.4 two years ago and
it cost me $215.  Consider yourself fortunate.  Mine still works quite


well -- I am using it to enter this message -- and like most modems,
will be obsolete long before it wears out.  If my Internet provider
decides to upgrade to 28.8K, I will probably get one.  Otherwise,
since I can't use one yet, I'm not going to bother.

> 1.  Is the bps across the twisted pair wire actually running at 28.8 
or 
> 14.4 when 28.8 is invoked? Or is it just data compression?

The raw data rate for a modem will be from 110 to 28,800 baud (or
14,400 baud) depending on what the other side agrees on.  The rate
will be the lowest of whatever the two modems agree on. If you call up
a service that has only 14.4 modems, or 9600 baud modems, or even
2400, you will only get 14.4 or 9600 or 2400 even though your modem
can do more.  If both modems are 28.8 and both have their highest
speed enabled, you should see 28,800 baud before any compression
occurs.

The data is not sent at 28,800 bits per second, however.  Typically
the modem will divide up the telephone line into six or more channels,
and run each channel at 2400 to 4800 bits per second.  By multiplexing
six channels at 2400 baud, you get 14,400 baud, etc.

> 2.  What kinds of host supports 28.8K?  I only connect up to my 
> university's computer which only runs at 9.6K max.

Your university may have so much load they can't run faster than 9600,
or the terminal controller might not be able to handle it.  Many
mainframes can't do I/O faster than some otherwise slow speed by
comparison.  When a IBM Sierra mainframe came out, a 9600 baud modem
probably cost as much as an ISDN BRI interface does now; hundreds or
thousands of dollars, so the port controller was probably set up with
that as the maximum.  The school might not have money in the budget to
upgrade modems, or the hardware might not be able to support those
kind of speeds, or it could be the administration was waiting until
the 28,800 speed was standardized by ITU, as some modems used
proprietary methods to communicate about 14.4 and thus you might need
the same brand at both ends.  You might ask them if they plan to
upgrade to 28.8 now that the ITU has standardized the method of
delivering 28,800 baud.

> 3.  What is the speed of fax machines?

There are two speeds for transmissions.  First, when the connection is
being set up, each side will send an identifier sequence.  I call it
the "answerback" after the similar sequence sent by a telex machine.
This identifier sequence is called a TTI or CSI.  One of these will
typically appear in the log that the fax machine prints after 20-40
transmissions indicating the identifying machine.  The other is the
telephone number or other identifier that appears in the display
window.  The two items may be different.  This information is
transmitted by each machine at 300 baud, which is okay since it is
typically no more than 60 characters for each side.  The sending
machine then increases its speed and the transmission takes place in
the equivalent of "half duplex" mode, except that the recipient
machine typically acknowledges the end of each page and end of
transmission.

The ITU standard for fax machine transmissions supports 4800, 9600,
12000, and 14400 baud, but typically a fax machine that does printing
will do 9600 tops, and can be downgraded to 4800 if line conditions
are bad. 12000 and 14400 are typically for fax modems in computers.

> 1.  The Supra has a nice display (external version for the PC) that 
> shows the mode of transmission.

> 2.  However, I found that it required a different initialization 
string 
> than that suggested as default for modems that are Hayes compatible.  

The strings for each modem are because they all do different things,
and thus, to enable those features you have to set certain values.
For example, you can do a feature called "port locking".  Currently,
my terminal program sends and receives data to and from my modem at a
"locked" speed of 19200 baud.  The modem will transfer data to and
from the computer at 19200 baud, whether the connection at the other
end is 110 all the way to 14400.

The typical rule is to indicate every connection is at 19200.  I can
set a switch register and the modem will also report the actual
connection speed.  I can set a switch and have it enable or disable
data compression, and I can enable or disable error correction.  And I
can set switches so that it tells me whether the other side allows or
does not allow compression or error correction, or force error
correction or compression.

For example, when playing DOOM over a modem, the modem will run at
9600 baud (later revisions of the driver support 14,400). The modems
must not use data compression or error correction (because the extra
time to do this can lose synchronization between the two computers),
and the setup string for my modem will specifically disable these
features.  At the end of the game, the driver will issue an AT Z HO to
disconnect the line and reset the modem to the default settings.

If I have caller ID service on a line, I can enable the modem to send
the data after the "RING" message.  I can enable the data in 
hexadecimal 
display digits, or I can enable it as ASCII text.  I can also tell the
modem to resend the last Caller-ID string it got, and I can tell it to
resend it in hex or ASCII, even if I had already received it using the
other mode.  I can also turn off reception of Caller ID data.

If I want the modem to send or receive facsimile data, the program
must use the AT&F prefix with certain commands to tell the modem to
either place a fax call or receive a fax.  Every feature in a modem
requires controls on it in order to enable or disable them as needed
in a particular instance or application.

Oh, yes, one more thing.  The alleged claims of data compression
giving throughput rates of 50+K and 110K on 14.4 and 28.8 modems is
sheer fantasy.  If you were sending a 100,000 byte file consisting of
all spaces, or all the same character, you might see those kind of
rates.

On my 14.4K modem, on ASCII text files, if I use a locked port at
38,800 baud, and enable compression I can see transfer rates of as
much as 3000 cps in rare cases, and typically around 1800 cps if the
data compresses well.  For binary and compressed ZIP archive files, I
have generally seen average transfer rates in the 1600-1620 cps.

For a 28.8K modem, you can expect to probably see rates around
3200-3400 cps, depending on the content of the material, if the other
side uses a 28.8K and can stuff it fast enough to keep the line
loaded.

MCI Mail supports 14,400 baud on their dialins, but I typically see
rates in the 700-1000 cps rate, probably because their VAX machines
are heavily loaded.  Occasionally I'll see rates as high as 1200 cps.

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

From: TELECOM Digest Editor <telecom@eecs.nwu.edu>
Subject: New Archives Email Feature
Date: Tue, 07 Feb 1995 01:00:00 CST


Monday evening I installed a new feature in the Telecom Archives Email
Information Service software called AREACODE. This allows the user to
enter one or more areacodes and get back email telling where the code
is located.

This is just an additional command installed in the software, used in
the same way as the other commands. You can insert as many areacodes
as desired and get back responses on each one.

If you are not already familiar with the Telecom Archives Email 
Information
Service, you can request a help file explaining how to use the 
service.
Send email to tel-archives@lcs.mit.edu. The subject does not matter.
In the text of your message, at the left margin, enter these commands
on your first use of the program:

REPLY yourname@site
HELP
INFO
END

The REPLY command *must* be first, and END *must* be last. What you 
put
in the middle depends on what you are seeking. The help file you will
get in return explains the other commands.

To use the new AREACODE command, it would look like this:

REPLY yourname@site
AREACODE 208 701 302 509   (or whatever areacodes you want to check).
END

Watch for a response in email, typically a minute or two later.  Other
interactive commands you can use are:

SEARCH <string>   to search the back issues of the Digest for subject
                  and author names since 1989 forward.

GLOSSARY <string> to search the several glossaries on line in the 
Archives
                  checking for abbreviations and telecom terms you 
want
                  to learn about.

The help file will explain it all when you order it and INFO. Carl 
Moore
keeps the area codes files up to date, so blame him, not me if you 
don't
find all the newer codes there.


Patrick Townson

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

End of TELECOM Digest V15 #82
*****************************

                         
