A Beginner's Guide to the Internet/INTERNET.ISO/text/telediag/tc13-100.txt

Text File | 1993-02-16 | 22.7 KB | 571 lines

TELECOM Digest     Tue, 16 Feb 93 02:39:20 CST    Volume 13 : Issue 100

Index To This Issue:                      Moderator: Patrick A. Townson

    Re: Searching For PPP Pointer RFC (Paul Robinson)
    Re: AT&T Are You Listening? (David G. Lewis)
    Re: Strange Long Distance Problem (Carl Oppedahl)
    Re: Standard Dialing Plan (Garrett Wollman)
    Re: What Would Be Required to Compile 'Secret #' FAQ? ([e-mail])
    Re: Procedure to use 800-321-0ATT (Ben Cox)
    Re: What Could Cause Jitter in a Voice Channel (Al Varney)
    Re: What Number do I Dial From My Phone to Get My Phone to Ring? (Oppedahl)
    Re: Sharing One FAX Card Among Several Voice Lines (Mark James)
    Re: Internet Access From Qatar? Anyone? (Carl Oppedahl)
    Internet Access Wanted in Cedar Rapids, IA (Dave Fox)
----------------------------------------------------------------------

Date: Mon, 15 Feb 1993 23:16:08 -0500 (EST)
From: Paul Robinson <[e-mail]>
Reply-To: Paul Robinson <[e-mail]>
Subject: Re: Searching For PPP Pointer RFC


In Telecom Digest 13-98  [e-mail] (Sam) wrote:

> Does anyone know if an RFC has been published for Point to Point
> Protocol, the updated synchronous/asynchronous SLIP?

I got these from the copy of the RFC index I downloaded from
NIC.DDN.MIL two days ago.  Using a text editor, I looked up 'PPP' and
'point-to-point':

1378  The PPP AppleTalk Control Protocol (ATCP).  1992 November
1377  The PPP OSI Network Layer Control Protocol (OSINLCP).  1992 November
1376  The PPP DECnet Phase IV Control Protocol (DNCP).  1992 November
1333  PPP link quality monitoring.  1992 May
1332  PPP Internet Protocol Control Protocol (IPCP).  1992 May
1331  Point-to-Point Protocol (PPP) for the transmission of multi-protocol
      datagrams over point-to-point links.  1992 May
1220  Point-to-Point Protocol extensions for bridging.  1991 April

The following are all obsoleted by the above, but you may want
to look at them:

1172  Point-to-Point Protocol (PPP) initial configuration options.
1171  Point-to-Point Protocol for the transmission of multi-protocol
      datagrams over Point-to-Point links.
1134  Point-to-Point Protocol: A proposal for multi-protocol
      transmission of datagrams over Point-to-Point links.

Anyone who will ever use the Internet RFCs should have a copy of the
index.  It is revised as new RFCs are issued. There is also a mailing
list to receive notification when new RFCs are issued.  The index
(rfc-index.txt) and the RFCs (rfcxxxx.txt) can be obtained by
anonymous ftp from NIC.DDN.MIL in subdirectory 'rfc'.

To get it, or any of the RFCs, you send a message to:

[e-mail]  with the following text:

send rfc-index.txt
send rfc1378.txt
send rfc1377.txt

etc.

For those without Internet mail access, many of the Internet RFCs have
been stored by me and others on a BBS called 'Brodmann's Place' at +1
301-843-5732 All of the above RFCs were either there before or have
been uploaded before this message was posted.


Paul Robinson -- [e-mail]


[Moderator's Note: My thanks also to Steven L. Johnson <johnson@tigger.
jvnc.net> for supplying identical information from the index.   PAT]

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

From: [e-mail] (david.g.lewis)
Subject: Re: AT&T Are You Listening?
Organization: AT&T
Date: Mon, 15 Feb 1993 22:20:48 GMT


In article <[e-mail]> jack.decker@f8.n154.z1.
fidonet.org (Jack Decker) writes:

> ... in many cases if you are going to have trouble on a call, the
> trouble is most likely to be in the local telco's lines from their
> point-of-presence (of which there is often only one per LATA) to their
> local exchange, and ALL the carriers use those same lines to complete
> calls.

Not necessarily.  Assume, for the moment, that all three major IXCs
(heck, let's add WilTel, too -- the four largest IXCs) have 100% fiber
optic transmission facilities.  (Not true, but let's assume.)
Therefore, differences in transmission quality can only come from
three places:

1. The local loop from the premises to the End Office;

2. The LEC interoffice plant from the End Office to the Access
   Tandem, if any;

3. The (LEC-owned, IXC-purchased) access plant from the EO/AT to the
   IXC switch.

The first, the loop plant, is going to be the same regardless of the
IXC.  However, other LEC facilities may differ depending on the IXC
selected, *not* solely on the random chance of which trunk group is
selected for routing on a given call.

First, exchange access arrangements differ among IXCs.  AT&T has a
deep deployment of direct connection to the Equal Access End Office.
MCI, Sprint, WilTel, and other IXCs have comparatively little
connection to EAEOs, and concentrate most of their traffic through an
IXC.  (I use the word "comparitively" because I don't know the
absolute magnitude; I know that several years ago it was little to
none, but I don't know if that's current.  Compared to AT&T, though,
it is relatively low.)

Therefore, a call using AT&T will often route directly from the EAEO
to the AT&T network.  A call using another IXC will usually route from
the EO over LEC interoffice facilities to an AT, and then to the IXC
switch.  Adding the LEC interoffice facilities which are not present
on the call being routed to AT&T will add some (perhaps small, perhaps
large, depending on the type of facilities) degradation.

Second, the facilities from the LEC switch (EO or AT) to the IXC
switch are, obviously, different for different IXCs.  They are
provided by the LEC, and likely meet the same criteria for sound
quality, but they are different because the selected IXC is different.

Third, a not-insignificant number (I don't know the exact number; I'd
guess it's more than one, less than one hundred ...) of AT&T's
switches are located in buildings shared by AT&T and the local BOC, as
a holdover from pre-divestiture days.  The exchange access facilities
from the BOC switch to the IXC switch, in this case, are intraoffice
facilities which are inherently less subject to degradation than are
interoffice facilities.  That's probably not really fair to other
IXCs, but if the FCC's NPR on colocation goes through, I suppose
everyone could get into that biz.

> If you try a call over MCI and it doesn't work, and you then try to
> complete it over AT&T and it does, that doesn't necessarily mean that
> AT&T is better, it just means you got a different circuit from the
> local telco.

My point is that you may have gotten a different circuit from the
local telco *because* you used AT&T.

Disclaimer: ("claimer"?)  I work for AT&T and take a certain amount of
pride in my employer; however, I have tried to limit my comments to
factual descriptions of network access arrangements.


David G Lewis                              AT&T Bell Laboratories
[e-mail] or !att!goofy!deej     Switching & ISDN Implementation

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

From: [e-mail] (Carl Oppedahl)
Subject: Re: Strange Long Distance Problem
Organization: PANIX Public Access Unix, NYC
Date: Mon, 15 Feb 1993 21:44:04 GMT


In <[e-mail]> [e-mail] (Ken Jongsma)
writes:

> I've been having an interesting problem over the past two days. The
> symptoms are as follows:

[stuff omitted]

> - Prefacing the call to 1 805 395 xxxx with 10288, 10333, 10222
>   makes no difference, I still get a fast (trunk) busy.

Suggests it is the fault of your local telco, not the long-distance
carrier.

> A call to Michigan Bell repair yesterday generated the suggestion that
> I call Sprint repair.

Typical of the local telco to pass the buck.

> I suspect a problem with Michigan Bell and my local switch, but
> getting through to them is a lost cause.

Continued in the next message...
---
 * PCB/UseNet Gateway from Sparkware #3
<=============================================================================>
    To:  ELIOT GELWAN             Date: 02-16-93 (05:21)
  From:  USENET GATEWAY           Message:  94474      Refer:  0
  Subj:  TELECOM DIGEST V13 #100  Conf: 700 (EMAIL)
-------------------------------------------------------------------------------
·  Newsgroup: Private mail
·       From: TELECOM
·    Subject: TELECOM Digest V13 #100


(Continued from the previous message)

Maybe you could embarrass MI Bell into action by filing a complaint
with the FCC, saying that MI Bell is being discriminatory in its
provision of access to the long-distance network.


Carl Oppedahl AA2KW  (intellectual property lawyer)
30 Rockefeller Plaza   New York, NY  10112-0228
voice 212-408-2578     fax [phone]


[Moderator's Note: The other thing he might try is to simply not pay
the portion of the bill added on for 'connection to the network' --
you know, that $3-something charge they tack on every month to make up
for what they no longer collect on long distance. When asked why, say
"because Michigan Bell is not providing total access to the network,"
and that when they begin doing so, you will begin paying. Don't worry,
they won't cut you off for non-payment; you'll cause a few snickers in
the business office, and it will get fixed.  PAT]

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

From: [e-mail] (Garrett Wollman)
Subject: Re: Standard Dialing Plan
Organization: University of Vermont, EMBA Computer Facility
Date: Mon, 15 Feb 1993 21:57:10 GMT


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

> Sorry, I disagree.  How can you dial 1 + ten-digits and not have
> intended to dial a ten-digit number.  How often do people really dial
> all ten digits and intend to only dial seven digits?  And if they do
> dial ten digits by mistake, how often was the incorrect NPA dialed?

While I agree with Al's position in general, consider the following:

I meant to dial:  1 803 793 xxxx
I actually dial:  1 802 793 xxxx

If 10D dialing within my NPA is not trapped, I end up making an
expensive New England Tel. toll call, rather than a cheap AT&T call to
South Carolina.

(Now does anybody want to share stories of wrong area codes when
calling into the NANP from outside?  I can remember calling home (at
the time, 802 434 xxxx) from Finland, and getting someone at 902 434
xxxx, which is in Nova Scotia, instead.  "Hi!" "Who's this?".  Note
that this was a credit-card call, and the procedure was to call the
international operator (92022 when I was there), and read out the
destination number and calling card number to her.  I soon learned of
AT&T's USA Direct(tm) service, and decided to use that instead ...)


Garrett A. Wollman   [e-mail]
uvm-gen!wollman      UVM disagrees.

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

Date: Mon, 15 Feb 93 12:48:33 EST
From: [e-mail]
Subject: Re: What Would Be Required to Compile 'Secret #' FAQ?
Organization: Ideology Busters, Inc.


In article <[e-mail]> Chris Taylor <[e-mail]>
writes:

> RINGBACK:    445<your number>
> HEAR YOUR NUMBER:
>        958

Maybe I was asleep or something ... could someone tell me why these
services would be useful?

Is there really sufficient demand for these to justify someone, other
than the phone company, doing this?  By demand, I mean consumers who
are willing to pay for "hear your number", "ring back", and maybe
others.  How much would be a "reasonable" amount; $0.25 per call?
More, or less?

And how could this be billed to the "correct consumer" anyway?  If
this were done via a toll-free 800 number, how would the provider
collect payment?  If it was done via a 900 number, does the provider
always get the correct phone number to play/call back?  Is this
easier than I imagine or will it be pretty difficult?

> [Moderator's Note: One of the things you'd have to contend with is the
> frequency with with which 'ringback' and in particular 'hear your
> number' code numbers are changed. 'They' do not like people outside
> the telco to know these or use them.

True, but if it was an outside business doing this could the telcos
force it to stop?

Are there any reasons why this would be a dangerous service to sell?


[Moderator's Number: *If* telco wanted to sell it (and really, telco
would be the only organization able to do it with close to 100 percent
accuracy; others would have to read the ANI or the Caller-ID and get
the detail from those sources which is not always correct), they'd
find a way to charge a premium for it much like IBT does with the Name
and Address Reverse Listing Service here for 312/708 (312-796-9600).
Calls to 312-796 (so far as I know, '9600' is the only resident on
that exchange) are 35 cents per call, with two inquiries allowed and
no guarentees you will get any information if the number you pass is
non-pub, etc. (You still get charged.) Telco does sell ringback in
some places through variations on an 'intercom feature' offered as
part of 'Intellidial' and similar packages.

Regards 'hear your number', telco does not like having that available
to the general public. It has to be available since linemen and
technicians need to sort out wire pairs they are working on, but given
the general public's bent for fraud and assorted mischeviousness,
letting them match up the wires (of others) with a specific number in
an authoritative way would lead to problems. There are security
problems inherent with telling anyone who happens to be on the wire
what the 'number' to the wire is.  It is not like your wire pair runs
straight to the CO without being multipled in every basement and
janitor's closet over a two block area surrounding where you live.
Anyone -- literally -- could clip on those wires and dial 'hear your
number'; and it would be 'your' number they were hearing, and most
likely you against whom fraud was perpetrated.  If others did it via
900 or whatever, there is no law against it, but they would be
charging, and most people who ask this ageless question here in the
Digest are looking for *free* ways to get the info.  PAT]

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

From: [e-mail] (Ben Cox)
Subject: Re: Procedure to use 800-321-0ATT
Date: Mon, 15 Feb 1993 20:12:08 GMT
Reply-To: [e-mail] (Ben Cox)
Organization: Ancient Illuminated Sears of Bavaria


Pat writes:

> [Moderator's Note: After dialing 800-321-0288, you hear the AT&T
> tones, and the robot operator announces, "AT&T ... please enter the
> number you are calling, or zero for an operator."  After entering the
> number you are asked to enter your card number. It is basically the
> same as any other credit card call.  Persons who have experiences with
> this are requested to write.   PAT]

Yes, that's exactly how it works.  Of course, once you hear the tones
you don't have to wait for the robot to finish its spiel.  :)


Ben Cox         [e-mail]

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

Date: Mon, 15 Feb 93 21:56:04 CST
From: [e-mail]
Subject: Re: What Could Cause Jitter in a Voice Channel
Organization: AT&T Network Systems, Lisle, IL


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

> In article [e-mail], [e-mail] (Tracy Ching
> <[e-mail]>) writes:

>> While sending a 1KHz tone over that voice channel, the other end is
>> jittering (changing phase constantly) and also slightly changing
>> amplitude.  The "gurus" who administer the thing say there is nothing
>> that can be done to fix it.  I just want my clear channel.

>> I'm quite sure my 1KHz tone is pure, i.e. no jitter from the source.

> Digital systems experience an impairment known as timing jitter.  This
> is caused by the accumulation of variations in timing of a digital
> signal.  A string of repeaters adds small timing errors due to the
> clocks in each repeater and the addition/removal of 'stuffing bits' in
> async muxes (like most M13's).  It is possible to add buffers to
> retime the signal at each end, de-jitterizing the signal, but they are
> pretty expensive.

   Note also that the mu-law PCM sampling algorithm can itself lead to
some distortion when near-zero samples are encoded.  Particularly with
1 and 2 kHz tones, where you can be very slightly out of synch with
the 8kHz sampling rate, and see the results as quantization noise
coupled with jitter.

   This is why the Digital Reference Signal for digital facilities is
1004 Hz (and I have heard that some standards folks want 1008 Hz??).
This offset from 1000 Hz means only an infrequent sample hits that
zero-crossing area with a sample of +0 or -0.

Continued in the next message...
---
 * PCB/UseNet Gateway from Sparkware #3
<=============================================================================>
    To:  ELIOT GELWAN             Date: 02-16-93 (05:21)
  From:  USENET GATEWAY           Message:  94475      Refer:  0
  Subj:  TELECOM DIGEST V13 #100  Conf: 700 (EMAIL)
-------------------------------------------------------------------------------
·  Newsgroup: Private mail
·       From: TELECOM
·    Subject: TELECOM Digest V13 #100


(Continued from the previous message)

   Also, are you sure there isn't any T1 bit-robbing of A/B bits
occuring?

   The ultimate test would be for you to send only binary samples of
known value and see if they arrive without change.  If so, then it's a
problem with the encoder and/or decoder (and the jitter).


Al Varney - just my opinion, of course.

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

From: [e-mail] (Carl Oppedahl)
Subject: Re: What Number do I Dial From My Phone to Get My Phone to Ring?
Organization: PANIX Public Access Unix, NYC
Date: Mon, 15 Feb 1993 21:40:07 GMT


In <[e-mail]> [e-mail] (John V.
Jaskolski) writes:

> I presently live in Boston.  When I used to live in Milwaukee, WI, I
> could dial "97" and the last five digits of my telephone number, push
> down and release the hook, hear a tone come over the line, hang up,
> and my phone would ring.  Does anyone know what I can dial from Boston
> to do the same thing?  In other words What number do I dial from my
> phone to get my phone to ring? (From Boston)

According to Part 68 of the FCC regulations, the local telco is
supposed to tell you how to make your line ring back ... so that if
you have installed your own phone jacks you can test them out.

The idea is to put do-it-yourselfers on a level playing field with the
telco inside-wiring installers.  Otherwise, if they keep the number
secret, their installers would have an unfair advantage.

So the way to get the answer to that question is ... ask your local
telco.

Now, I can tell you that I have never, never, never, in three cities
found a local telco that will spill the beans on this number just for
the asking.  I have always had to ask to talk with a supervisor, then
the office, manager, etc. etc.  And in many cases I have had to
photocopy the section of Part 68 that says this, and fax it to them.
But I have always eventually gotten it.

Here in Manhattan the numerical sequence to dial differs from one
central office to the next.  Seemingly no two are the same.

Good luck.


Carl Oppedahl AA2KW  (intellectual property lawyer)
30 Rockefeller Plaza    New York, NY  10112-0228
voice 212-408-2578     fax [phone]


[Moderator's Note: Telco need not provide an automated service for
this purpose or tell you how to access the automated service. They
need only to make your bell ring on request. In other words, the
business office could have told you to ask the operator to ring you
back. That would have met the requirements.  PAT]

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

Date: Tue, 16 Feb 93 12:46:09 GMT
From: [e-mail] (Mark James)
Subject: Re: Sharing One FAX Card Among Several Voice Lines
Organization: Dialogic (N.Z.) Ltd, Auckland, New Zealand


In article <[e-mail]> [e-mail] (Elizabeth
Fong Wah Chan) writes:

> Presently, my company plans to install a voice processing system to
> do voice mail, audiotex, and faxing.

> We have purchased a four-line voice processing board and a software
> development package.

> Since we want to allow callers to be able to send and receive faxes in
> addition to voice processing [...]
> I wonder if there is some kind of simple switching equipment that
> allows sharing of one fax board among all four phone lines.

You don't mention the brand name of your four-line board.  If it's a
Dialogic D/41, you can add a single AMX/81 board that will connect any
of the four lines to any other, or to any of eight local telephones,
fax machines, modems or what have you.  You should find out whether
your software development package will support such a configuration.

Disclaimer: I work for Dialogic.  I presume (but don't know) that
competitors offer similar solutions to Elizabeth's problem.


Mark James  <[e-mail]>  **[ Opinions are mine ]**
Dialogic (N.Z.) Ltd.                Voice:  [phone] ext 27
Auckland, New Zealand               Fax:    [phone]

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

From: [e-mail] (Carl Oppedahl)
Subject: Re: Internet Access From Qatar? Anyone?
Organization: PANIX Public Access Unix, NYC
Date: Tue, 16 Feb 1993 01:11:09 GMT


In <[e-mail]> [e-mail] (BINOY P
JAMES) writes:

> Anybody know if I could access Internet from Qatar, in the Middle
> East?  How about Bitnet at least?

There is a newsgroup which you might not know about, called
alt.internet.access.wanted.  It is perfect for your query.  (I realize
you may not have access to that group, in which case that would be why
you did not post to it.)  Anyway, if you can I suggest you post to
that group.

If you are not able to post to that group directly, you may wish to
consider using one of the services that lets you post via email.  For
example, you could post to:

[e-mail]

and state in your posting that you would like to get responses via
email.

Best of luck.


Carl Oppedahl AA2KW  (intellectual property lawyer)
30 Rockefeller Plaza   New York, NY  10112-0228
voice 212-408-2578     fax [phone]

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

From: [e-mail] (Dave Fox)
Subject: Internet Access Wanted in Cedar Rapids, IA
Organization: Division of Biostatistics, WUMS, St. Louis, MO
Date: Mon, 15 Feb 1993 20:13:27 GMT


I am looking for an INTERNET newsfeed for a friend in the Cedar
Rapids, IA area.  Please e-mail me any info.

Thanks in advance.


[e-mail]


[Moderator's Note: You too might try Carl Oppedahl's advice in the
message just before this one.   PAT]

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

End of TELECOM Digest V13 #100
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