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TELECOM Digest     Tue, 12 Sep 95 15:58:00 CDT    Volume 15 : Issue 377

Inside This Issue:                           Editor: Patrick A. Townson

    FCC Rules Against Carrier Kickbacks to ESPs (Michael D. Sullivan)
    An Idea for LECs to Communicate Area Code Splits (Richard Layman)
    # Means #; Number Means a Telephone Number (Mark J. Cuccia)
    OC-X to Modem at AOL (Stephen Balbach)
    Re: Variable Length Phone Numbers (Jan Ceuleers)
    Re: Variable Length Phone Numbers (db@barc.com)
    Re: Variable Length Phone Numbers (Linc Madison)

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



The FCC staff issued a letter ruling on September 1 that ruled against
a variety of techniques used by enhanced service providers to provide
"services" such as international dial-a-porn and free BBS/internet
access by means of kickbacks to the ESP and/or restricting access to
the ESP to a single IXC.  Here's the text of the ruling:

      -----------Text of FCC decision------------

                     Federal Communications Commission
                         Washington, D.C.   20554

                             September 1, 1995

                                                                 DA 95-
1905

Ronald J. Marlowe, Esq.
Cohen, Berke, Bernstein, Brodie,
 Kondell & Laszlo
Terremark Centre
19th Floor
2601 South Bayshore Drive
Miami, Florida  33133-5460

Dear Mr. Marlowe:

     This is in response to your informal request for a staff ruling
regarding the legality of certain information and/or entertainment 
programs
provided pursuant to tariffed rates for international communications
services.   Your inquiry is made on behalf of clients who apparently are
interested in tariffing "international long distance services" for the
transmission of information and/or entertainment programs.  You present
scenarios whereby calls to foreign destinations providing audio 
information
programs would be transmitted through three different dialing sequences: 

(1) 10XXX + international number; (2) 1-500-NXX-XXXX; or (3) 1-700-NXX-
XXXX.  

In each case, the calls would be transmitted by an entity authorized
to provide international direct dialed telecommunications services
pursuant to Section 214 of the Communications Act (the Act) at a
tariffed rate.  Calls to the international information programs would
be billed to telephone subscribers at that tariffed rate as standard
toll charges.  No charges would be assessed by the information
provider directly to the caller or subscriber.  You ask whether the
legality of the arrangement would be affected if: (1) the carrier
remits a portion of the transport charge to the party advertising the
destination number; or (2) the carrier remits a portion of the
transport charge to the destination entity for providing the
information.  You also inquire whether the arrangement is lawful if
steps are taken so that the destination number could not be accessed
through any other carrier, and whether such calls may be billed on a
separate page with consumer disclosures as non-deniable (so that
disputes do not lead to disconnection of service).

     As explained below, the staff concludes that it is a violation of 
federal law for any entity to provide tariffed common carrier 
communications 
services in an arrangement -- whether domestic or international --
where charges are assessed for calls to information programs in the
manner you describe and/or when the carrier blocks access to a number
from other carriers.  Common carriers engaged in such practices are
not providing common carrier communications services in a just and
reasonable manner as required by Section 201(b) of the Act, and are
violating both the letter and spirit of Section 228 of the Act.

     Traditionally, information and entertainment programs have been
provided to telephone subscribers at rates exceeding the tariffed
transmission rates charged by the transmitting common carrier.  Such
interstate information services are regulated as "pay-per- call"
services under the Telephone Disclosure and Dispute Resolution Act
(TDDRA) (codified at Section 228 of the Act) and implementing
regulations adopted by both this Commission and the Federal Trade
Commission.  Our rules require that all pay-per-call services must be
provided on the 900 service access code.  Common carriers involved in
either transmitting and/or billing subscribers for pay-per-call
services are subject to several statutory requirements intended to
ensure that consumers are able to prevent access to or charges for
unwanted information services.  Specifically, the TDDRA requires
carriers to offer telephone subscribers the option of blocking access
to pay-per-call services and prohibits the disconnection of basic
telecommunications services for failure to pay pay-per-call charges.
While the statute establishes a comprehensive system for federal
regulation of pay-per-call services, it specifically exempts from
pay-per-call status "any service the charge for which is tariffed" and
services offered pursuant to a "presubscription or comparable
arrangement."

     In determining whether an entity licensed as a common carrier may
lawfully provide service in the manner you describe, we note first
that information programs should not be tariffed as common carrier
services.  Rather, common carriers may offer information programs only
as non-tariffed "enhanced" services in accordance with Section 64.702
of the Commission's rules.  Moreover, it is a basic and central
principle of common carriage that a carrier may provide tariffed
service only as an objective conduit of a customer's communication,
without influence or control in determining either the content of the
communication or the destination of a customer's calls within its
authorized service area.  See Amendment of Parts 2, 91, and 99 of the
Commission's Rules Insofar as They Relate to the Industrial
Radiolocation Service, Report and Order, 5 FCC 2d 197, 202 (1966).
Through payments to an information provider or destination entity
(other than standard settlement payments), a carrier would abandon
objectivity and acquire a direct interest in promoting the delivery of
calls to a particular number for the provision of a particular
communication.  This precept applies regardless of the particular
dialing sequence used to place calls.  Also, any carrier that is
involved, either directly or indirectly, in blocking access to the
called number by other carriers or in determining or influencing the
content of the communications delivered through its network is not, we
believe, offering a common carrier service.  We recognize that long
distance carriers lawfully assign numbers in limited circumstances and
are the sole carrier to transport calls to such numbers.  Restricting
access to a particular telephone number that has been assigned for
access by multiple carriers, however (or creating fictitious numbers),
so that calls to that number can be completed only on one carrier's
system is anticompetitive and an unjust and unreasonable practice,
because that action deprives consumers of their right to use their
preferred carrier.  

A carrier may lawfully provide service to information providers is
only if it has absolutely no involvement or interest in the
communications made through its network and does not engage in any
action to encourage calls to a particular number or limit access to
that number to callers using its transmission services.  In summary,
in the service scenarios you describe the carrier would appear to be
providing an enhanced service, not a basic common carrier communications 
service.  Accordingly, imposing tariffed charges for the service would
be an unjust and unreasonable practice under Section 201(b) of the
Act.  This conclusion is reinforced by the implication that your
clients apparently plan to deliver calls only to a limited group of
people (information providers), rather than making their service
available to call any number at competitive rates using standard
communications operator and billing procedures.

     The services you describe are also unlawful under Section 228 of
the Act and the Commission's implementing rules.  It appears from your
description of the proposed services that your clients desire to
operate within the "tariffed service" exception to the definition of
pay-per-call service, and thus evade the letter and spirit of those
provisions and the important consumer safeguards for information
services.  The Commission is committed to eliminating abusive
practices which deprive consumers of their statutory rights concerning
such services.  Although Congress exempted from the pay-per-call
definition services that are provided on a tariffed basis, we do not
believe that the service you describe is encompassed within that
exception.  The fact that the consumer does not directly pay the
information provider does not exclude the service from the definition
of pay-per-call if the payment is simply paid to the information
provider by the carrier and then recovered from the consumer through
the transport charge.  In this case, the transport tariff is a sham;
the consumer has, in fact, paid the carrier for transport and the
provider, albeit indirectly, for the information.  Section 64.1506 of
the Commission's rules requires that such calls be provided only on
the 900 service access code.  Clearly, Congress did not intend that
the carefully crafted provisions of the TDDRA and Section 228 of the
Act could be evaded by the arrangement you describe.

      The payment of commissions in this instance is not comparable to
carriers' payments to aggregators such as pay telephone owners.  Those
commissions simply compensate aggregators for their costs of making
services and facilities available to the transient public for its
communications need.  See AT&T's Private Payphone Compensation Plan, 3
FCC Rcd 5834, 5836 (Com. Car. Bur. 1988), recon. and review denied, 7
FCC Rcd 7135 (1992).  The Commission has found that such commissions
are a legitimate business practice so long as callers are not
prevented from using any other carrier to place a call.  Id., National
Telephone Services, Inc., 8 FCC Rcd 654, 655 (Com. Car. Bur 1993).  In
contrast, the proposed payments to information providers are expressly
designed to evade the consumer safeguards set forth in the TDDRA and
the Commission's rules.

     Finally, we note that carriers are issued certificates of
authorization under Section 214 of the Act when the Commission
determines that such issuance serves the public interest and
convenience.  We believe that the inherently evasive and anti-consumer
and anti-competitive actions that you describe are contrary to the
Section 214 mandate applicable to carriers providing international
service even absent specific violations of the Act and the
Commission's rules.  For example, assigning a 500 number to an
information provider for termination in a country where the
terminating carrier pays the provider to route calls to that location
would be, in the staff's view, inconsistent with the public interest
mandate in Section 214.  Thus, entities who have applied for or hold
such authorizations may place such applications or authorizations in
jeopardy if they conduct such activities.

     Because the staff believes that the calling arrangements you
describe would violate Sections 201(b) and 228 of the Act, and would
be inconsistent with the public interest considerations set forth in
Section 214 of the Act, we need not address the manner in which the
calls may be billed.  Carriers may not bill subscribers for unlawful
calls.

     This is a staff ruling issued pursuant to Section 0.291 of the
Commission's rules, 47 C.F.R.  0.291.  Applications for review must
be filed within 30 days of public notice of this action.  See 47
C.F.R.   1.115.

Sincerely,

/s/

John B. Muleta
Chief, Enforcement Division
Common Carrier Bureau


   -----------End of FCC decision------------


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


[TELECOM Digest Editor's Note: Very interesting, indeed!  Does this mean
that those services operating under what has been called 'The Nevada 
Plan'
are now illegal?  Is it now the case that all those dial-porns operating
out of Netherland Antilles, Guyana and elsewhere are going to have to
make it on thier own without their kickbacks from AT&T and the other 
carriers?  Are we now to assume that direct delivery of long distance
traffic direct from a carrier to a subscriber via T-1 -- eliminating the
possibility of non-subscribers (to that carrier) from reaching the 
called
party -- are now illegal?

Now, what will happen if a subscriber changes his legal status from that
of 'subscriber' to that of 'telco'?  By that I mean the telcos have
always exchanged traffic among themselves and compensated each other for
traffic carried through the others' facilities, etc.  Suppose instead of
being just an end-subscriber accepting traffic who is no longer able to
receive commissions from an LD carrier I become a telco and expect to be
paid for the traffic the LD carrier delivers to me for processing? 
Suppose
at my telco, my two (and only two) 'subscribers', i.e. the two women who
work the phone room are only allowed to make outgoing calls on a collect
basis, and I, as telco, file a tariff charging thirty dollars per 
minute.
My subscribers return calls to their clients -- on a collect basis of
course -- and I submit my billing tapes in the usual way. 

For example, heretofore, I 'reached out and touch a new friend' on a
conference bridge operating in Nevada expecting only to pay toll with
no additional charge. The carrier took care of compensating the bridge
tender with a kickback from toll -- now deemed illegal.  Suppose now I
take your call of one minute or less duration and I advise you that 
'your
call will be returned in one minute or less, on a collect basis, using
the services of the Bridge Telephone Company. All you need to do is
accept our collect call when your phone rings.'  Now the bridge tender
uses the telephone company which he owns to place calls to customers
on a collect basis at the rate he establishes. Presumably that will be
legal, where the (in my opinion) more straightforward kickback from
toll paid by the carrier is not?

Can it be then, that the clients of Integratel who do in fact go through
the formalities of actually calling back collect (as opposed to simply
converting the billing method in mid-stream) are operating legally?   
PAT]

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



Toby Nixon's post about the upcoming split of the 305 area code, made me
remember an idea I've thought about that LECs could use to communicate
area code splits nationally. 

Phone companies like NYNEX and Bell Atlantic, and presumably all the
others spend a lot of money communicating area code splits within their
regions, such as ads in the local newspapers which detailing the changes
in exchanges, and at least with Bell Atlantic, putting (I seem to 
remember) printing on the back of the phone bill envelope listing the 
exchanges that were now part of the new area code.  

Why don't the LECs work together to use the billing envelope to
communicate area code splits nationwide?  Sure that might not get to
everyone who needs to know in a business, but it would get the word
out to most every household in the U.S., for probably not that much
money when you think about.

For example, the September phone bill envelope I get from Bell Atlantic
could break out the 305/954 split, and list the exchanges that are now
going to be in 954. BellSouth could do the same for the 703/540 split in
Virginia, etc.  I could then check my databases, address books, etc. 

Although printing a special insert would be expensive, and 
unfortunately, 
probably ignored by many, I don't think people would ignore the actual 
envelope, and the printing on it.

Similarly, there could be a statement on all the envelopes about the
new types of area codes like "334" and why organizations need to take
steps to deal with the implications to their calling systems.  Then
there might be fewer problems down the line.  Although I guess with
Ft.  Lauderdale getting one of those kind of area codes, most
businesses won't let it slide anymore -- cf "I don't call Alabama
anyway, why change our phone system now?"


                                                                                                    


Just a thought that BELLCORE ought to look into.


Richard Layman, Mgr., Business Development, and Research Producer
Computer Television Network, 825 6th St. NE, Washington, DC 20002
(202)544-5722 - (202)543-6730 (fax) - rlayman@capaccess.org
http://www.phoenix.net/~ctn  (... I know, it needs work)

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



With the recent thread of the '#' button's name, I have a gripe about
some people who post to TELECOM Digest and use phrases such as
'Calling an 800#'. PLEASE, please when wanting to abbreviate the
phrase 'Telephone Number' or 'Number' or NXX-XXXX or 'seven digits',
PLEASE don't use '#'.

The '#' is *also* a SPECIFIC touchtone button which has special purposes 
in 
numbering/addressing or telco functions (as well as private voicemail, 
auto 
attendant, etc).

For telco, '#' will time out a central office register when dialing
*variable-length* strings, such as NX-# instead of NX and waiting -- in
some Custom Calling applications -- # will indicate 'end-of-dialing' on
international strings. There is also 10-XXX-# 'cut-thru' dialing, and
one can get their Operator without having to wait for a time-out with
0-# (LEC) and 10-XXX-0-# (IXC indicated by 10XXX). 0-# does NOT
indicate zero plus the number- It means ZERO-POUND (or whatever you
call the '#' button).

'#' as a first entry key has been proposed (by Bellcore) for 'Facility
Codes' of the form #-XX. The 'XX' indicates a type of circuit or
transmission facility request, such as broadband, video, etc. #-56 is
proposed for requesting a 56 kbps circuit. Note that the other #-XX
codes aren't really assigned (yet) and there might possibly be no
standardization of their assignments/uses. I don't know what equipment
or codes ISDN users go by, but ISDN might just obsolete any plans for
#-XX facility codes, however.

For Historical Interest:

Back in the later 1960's (and early 70's), when AT&T/Bell-System was
planning on a future Picturephone service (the CRT type with Co-ax
loops/trunks), they planned on an initial '#' button to request a call
with the video loop as well as the regular audio telephone loop. One
would have called another picturephone as #-(1)-NPA-NNX-XXXX, local
picturephone calls as #-NNX-XXXX, and a Picturephone Assistance
Operator as #-0-(#). Service calls to Picturephone Information or
Picturephone Repair would have been dialed #-N11. Calls to regular
voice, non-video numbers, operators and services would continue to
have been dialed as normal, without the initial #. (The initial '#'
would also control AMA billing, as use of the video loop was charged
more than just the audio).

When abbreviating, lets try to say something like 0+num. or 0+nmbr. or 
0+A/C+num. for 0-NXX-NXX-XXXX (etc).

Just my 2-cents for the day, Pat.


MARK J. CUCCIA   PHONE/WRITE/WIRE:     HOME:  (USA)    Tel: CHestnut 1-
2497
WORK: mcuccia@law.tulane.edu          |4710 Wright Road| (+1-504-241-
2497)
Tel:UNiversity 5-5954(+1-504-865-5954)|New Orleans 28  |fwds on no-answr 
to
Fax:UNiversity 5-5917(+1-504-865-
5917)|Louisiana(70128)|cellular/voicemail


[TELECOM Digest Editor's Note: I use my heavy-handed editor's red pencil
to change that notation when it appears here. I get a lot of messages
where people write something like "I tried to call that #" ... and I
*always* change '#' to the word 'number' before releasing the article.

Speaking both of Picturephone and 'adult' information providers in the 
same
issue as we are this time, I am reminded of the fellow down in south 
Florida
who experimented with this for a few years in the 1980's. This guy was 
an
oldtime 'swinger magazine' publisher -- a 'paper dealer' as we used to 
call
them. You submitted ads and photos to his little magazine and he ran 
them
along with others. Then of course he made a commission as the 
reader/writers
exchanged personal correspondence based on the ads in the magazine, all
of which had to be forward through his remail service, at least the 
first
time. If a 'woman' (hint, hint! like the games they play on Compuserve 
CB
at night) submitted her picture and message to the magazine, she could 
be
assured of getting *TONS* of mail in her post office box a couple months
later from men all over the USA with various lewd photos and letters in 
re-
turn. This guy made his money from all the ten dollar fees to run your
picture and message in the magazine along with the one dollar bills
received to forward your response to the advertiser. He got paid from 
both 
directions. He decided one day to get into picturephone one day with 
live
people at his end who would chat and display themselves to callers.  

He bought up a huge surplus of the 'slow scan' type picture phones; the
ones that only change their image every ten or fifteen seconds. He 
offered
these on a purchase or lease basis to the subscribers of his magazine or
said they could purchase their own from whatever source, and of course
with billing approved by your credit card company, you could call in to 
chat 
with (and view) other members of his club ... I don't know whatever came 
of 
it or how successful it was, but it occurs to me if some of the present-
day
adult information providers got into picturephone there could be a lot 
of
money in it. 

Do you remember how, many years ago -- nah, you are all too young to
remember -- when tape players and cassette players were very new, how
the Columbia Record Club offered to send you a portable tape cassette
player -- for free, mind you! -- if you promised to join the Club and
purchase some minimum number of tapes each year?  More people got their
first tape cassette player (this was back in the era when we were seeing
a conversion from the old 'wire recorders' to magnetic tape recorders,
in the early 1950's) as a free gift from the Columbia Record Club (later
renamed the Columbia Record and Tape Club; nowdays Columbia House or
perhaps CBS Products, but still in Terre Haute, Indiana) by sending in
those coupons found in magazines and the Sunday papers ....

Battery operated tape players were the rage when I was in high school;
little pieces of magnetic tape in a case that would unwind onto another
spool and play the music therein ... more people became aware of that
'new technology' in the fifties because of taking the bait and signing
up with Columbia Record Club ... and please check the box if you want
classical, country and western, or whatever. I think you had to promise
to buy one tape each month for two years from the 'club magazine' sent
to you in the mail each month. If you did not return the card they sent
then you got the tape they selected and got billed for it anyway.

Now it occurs to me that if the telcos would really like to see picture
phone take off in a big way, they should cut a deal with the adult IPs
in a similar way. The IP could start a club and offer to supply picture
phones to new club members either free or at a greatly reduced price in
exchange for the new club member's promise to use the IP's services on
some regular basis. "Phone our service and chat with us at least once
each week for a year and we will send you at no charge a picturephone to
use when you call, because the young ladies and gentlemen here want to
be able to show you what they are doing as they chat with you about it."
Probably they would bill your credit card for a few hundred dollars and
send you the picturephone, then give you credit toward a certain number
of minutes/hours of service with them in the process. The IP's would
cut a deal with telco to get the units as cheap as possible, in the
same way Columbia Record Club cut a deal with (I think it was) the old
Zenith people to get those portable radios with the tape players built
in.  

The obvious drawbacks: the IPs would need to have legitimate people
there, and not the nasty ones (in real life) they use now.  grin.    
PAT]

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



I was speaking with someone who was speaking with a Bell Atlantic 
technician who does some of the work for AOL in Virginia.  Was curious 
how they bring in thier modem traffic and it is by OC-X (where X is some 
number Im not sure).  There has been a lot of talk about terminating 
modems using T1's, but what equipment is there to terminate at the T3 or 
OC level? Thats a lot of POTS lines.


Stephen Balbach  "Driving the Internet to Work"
VP, ClarkNet     due to the high volume of mail I receive please quote
info@clark.net   the full original message in your reply.

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



In article 6@eecs.nwu.edu, naddy@mips.pfalz.de (Christian Weisgerber) 
writes:

> First, let me state that I see *no reason whatsoever* why there can't 
be
> variable length phone numbers or why a switch would have to know the
> total length of the number. If you think there is a need for such
> restrictions, please explain why you think so. Your reasons are not
> obvious.

In situations where compelled signalling is used on one stretch of the
network, and non-compelled on the next, the switch that implements
this tandem function needs to know the exact number of digits or
implement a timeout (and leave the principle of compelled signalling).

Let me give you a specific example. A large Belgian organisation has
its own private network, which it uses for least-cost routing. This
private network uses R2 signalling (compelled). The PBX that routes
calls it receives from the private network back onto the public
network needs to know how many digits to expect, so that it knows when
to send the backward A-6 signal to indicate end-of-dialing instead of
the A-1 signal that asks for the next digit. This is needed both in
case the PBX is connected to the public network by means of analogue
trunks, and in the ISDN T0/T2 case where en-block sending is used.

If this PBX does not know the number of digits to expect, it must
always send the A-1 signal anyway, and send a pulsed A-6 signal if no
additional digit has been received within a timeout (see Q.442). This
is however an ugly kludge that can cause problems, both in the
signalling and in the ergonomy of the user.

We luckily don't have to struggle with this problem, since the Belgian
numbering plan is closed. However, if the private network is ever
going to be used for international least-cost dialing, we'll have a
problem ...

> I would also like to point out that in Germany, where I live, 
telephone
> numbers vary in length, in fact my voice number is +49.621.5870460 and
> my modem number is +49.621.583214, area codes vary in length (2..5
> digits), we have DID numbers of different lengths, and all of this
> without any kludges like second dial tones, timeouts, etc. Claiming 
that
> this is impossible is ridiculous in face of the facts.

You are quite right that this works fine if the signalling system is
compelled end-to-end.


Jan Ceuleers                             Alcatel Bell Telephone
hw/sw devt. engineer       Business Systems & Networks Division
vox  +32-3-450-3145                         fax  +32-3-450-3579
ceuleerj@bsg.bel.alcatel.be         #include "std/disclaimer.h"

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




In <telecom15.375.6@eecs.nwu.edu>, naddy@mips.pfalz.de (Christian
Weisgerber) writes:

Ok ... I didn't see the original posting, and am completely the layman 
here, but some things come to mind. (If I'm wrong, someone will 
correct me ... and I'll definitely learn something ... the reason I'm 
here in the first place :))

> First, let me state that I see *no reason whatsoever* why there can't 
be
> variable length phone numbers or why a switch would have to know the
> total length of the number. If you think there is a need for such
> restrictions, please explain why you think so. Your reasons are not
> obvious.

 ..stuff deleted...

> What must a switch do during call set-up? It receives dialing
> information (single or multiple digits) from an inbound trunk (or from
> the line card, if it is the caller's switch), and, after collecting
> enough of these, selects an outbound trunk. Further dialing info it
> receives is passed on to the switch on the outbound trunk. Note that
> no trunk line has to be actually connected yet. The destination switch
> collects dialing info until a line that it serves is identified, then
> it initiates a ring signal. Information about this is passed back the
> chain of switches to the caller's switch which locally feeds a "remote
> is ringing" signal. When the called line answers, again information is
> passed back to the caller's switch, and now the speech circuit is
> actually activated along the switch chain.

Is this truely how it works?  I can understand the written logic of
it, but see problems is several areas (1) dymanic routing of calls (2)
the anticipated 'number transportability' (3) routed calls like 800-
500-, etc.  It seems like in the above situation, the full number
would be required -up front-, or, as you mentioned, there would need
to be some time-out mechanism or 'end key' (like a #, *, etc), to
signify termination of the sequence.  Then again, I could easily be
all wet. If all numbers are available from the start, it seems like
the routing sequence would have less traffic than if there were a
continual transmission of the 'next' number involved in the dialing
sequence.  It seems to make sense logically.  But it also seems to
make sense that, at least currently, all numbers are required before
the sequence starts or wouldn't things like trunk busy signals, the
recordings about 'all circuits are busy' etc., come before we finished
dialing all the numbers? instead of waiting until all digits are
dialed first? (I remember some cities didn't require '1' before
dialing long distance, but I believe that's no longer true, so that
one is moot.)
 
> It also worked with the prior German
> phone technology, purely electro-mechanical switches. (That's relays,
> levers, etc. No transistorized technology whatsoever.) With that
> technology speech circuits were connected through to the next switch
> already during dialing, though.

Coming from the old crossbar, strowger switches as a kid, that seems
easier.  But even then, number lengths were fixed locally in my
hometown.  Five digit numbers were private lines or pbx's, six were
always party lines (same as five digits, and last was used to
differentiate the frequency of the ringing current to ring the correct
party).

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



Christian Weisgerber (naddy@mips.pfalz.de) wrote:

> Many posters, especially those from North
> America, insist on their belief that phone numbers have to be of
> constant length, otherwise one must have timeouts etc.

> First, let me state that I see *no reason whatsoever* why there can't 
be
> variable length phone numbers or why a switch would have to know the
> total length of the number. If you think there is a need for such
> restrictions, please explain why you think so. Your reasons are not
> obvious.

Within the North American phone system, telephone numbers must be of an
easily predictable length.  That is because much of the hardware in our
switching system is designed with the requirement that the originating
switch know when the subscriber has finished dialing, without inquiring
of the terminating switch.

Here is a sketch of what happens in North America when you dial.  The
letter N represents a digit other than 0 or 1.

011 - international call, expect minimum 7, maximum 12 digits to follow.
      Dialing must conclude with time-out or # key
01N - international call, but operator assisted; as above
00  - long distance operator; no further digits permitted
0   - local operator; dialing requires time-out or # key
11  - special service code -- exactly two digits follow, then restart
      dialing sequence.
10  - carrier selection code -- exactly 3 digits follow, then restart
      dialing sequence [this does not account for 101XXXX codes]
0N  - operator-assisted call, expect 0-NXX-NXX-XXXX
1N  - direct-dialed call, expect 1-NXX-NXX-XXXX
N   - examine first three digits for special cases (911, 411, etc., and
      in some areas an area code in the local area; in each of those
      cases, the number of digits to be expected is determined from the
      first three numbers dialed); otherwise, local number: NXX-XXXX

The only cases I know of where the total number of digits expected
cannot be determined from the first three digits dialed are
international calls (length varies) and in some areas the special case
141, which may be 1+411 or 1+41X-NXX-XXXX.  (In Southwestern Bell
territory, you dial 1+411 because there is a charge for the call.)  In
any case, with the exception of international calls, the number of
digits expected is known within the first four digits of dialing.

The advantage of this scheme is that the originating switch does not
need to open a path all the way to the terminating switch until dialing
has been completed.  The originating switch stores the entire number and
then opens a path and sends it along its way, or may open a path part
way through the dialing process and pass the initial digits and then
pass the remaining digits in real time.  In either case, it knows when
dialing is complete and can take the dialing register off that line.

Other countries have systems that use variable-length numbers without
requiring time-outs, because they open the path as the subscriber dials
and the terminating switch returns an indication that dialing has been
completed.

So, in sum, variable-length numbers work fine in systems designed for
variable-length numbers.  They work terribly in systems designed for
fixed-length numbers.  In order to use variable-length numbers in the
North American system, we would have to replace large segments of our
switching system.  We could implement a scheme that said, for example:

1212, 1213, 1214, 1312, 1314, 1305, 1713 -- eight digits follow
all other 1-NPA combinations -- seven digits follow
and program each local switch to know whether local numbers are seven or 
eight digits.

This would allow each area code to have EITHER seven-digit or
eight-digit local numbers, but not both.  That would require analyzing
at least five digits to determine expected length.  The other problem
with this scheme is that permissive dialing would be essentially
impossible: all numbers would have to be splash-cut at once in the
affected cities.

The other minor impediment is that not only every local C.O. switch
would have to be reprogrammed, but also every single PBX in North
America.  Given that we've seen how well PBX managers bury their heads
in the sand when faced with something as simple as NXX prefixes and
NNX area codes, expecting them to cope with eight-digit numbers in
some area codes would be a bit of a reach.


Linc Madison   *   San Francisco, California   *   LincMad@Netcom.com

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End of TELECOM Digest V15 #377
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