TELECOM Digest     Thu, 16 Dec 93 02:17:00 CST    Volume 13 : Issue 821

Inside This Issue:                        Moderator: Patrick A. Townson

   When is the BFI Flag Set by the Radio Subsystem in GSM? (Vartan Narinian)
   Calling Cards and Privately Owned Pay Phones (Javier Henderson)
   Portable Satellite Phone System (Paul Coladonato)
   Digital Phones of the Past (Bob Smith)
   Check From AT&T: Here's What to Do! (Robert A. Book)
   Re: New 411 System in Atlanta (Charles Hoequist)
   Re: Double Hunt Group - Possible? (Danny Burstein)
   Re: Ethernet Over Laser Link (John R. Levine)
   Re: Computer Cannot Receive From Modem (Arthur Rubin)
   Re: Computer Cannot Receive From Modem (Jay Hennigan)
   Re: NPA 905 Not Universally Recognized (Mark Brader)
   Re: A New Love Story (Solution) (Dror Lubin via Mark Brader)

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Date: Wed, 15 Dec 93 18:43:18 GMT
Subject: When is the BFI Flag Set by the Radio Subsystem in GSM?
Organization: Imperial College of Science, Technology and Medicine
From: [email protected] (Vartan Narinian)


Hello experts,

Could someone tell me when the BFI (Bad Frame Indication) flag is set
by the GSM radio subsystem? This is in GSM 05.05 which, unfortunately,
I don't have. I'm mostly interested about the Speech traffic case,
because this flag is used in the substitution and muting of lost
frames section (06.11).

My understanding is that the BFI is set when, after deinterleaving and
decoding, the CRC on the 50 class 1 bits indicates that there are
errors in those bits. However, I'm not sure about this and would like
someone to confirm it, if that's possible.


Thanks,

Vartan Narinian <[email protected]>
Electrical Engineering Department
Imperial College, London

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

From: [email protected]
Subject: Calling Cards and Privately Owned Pay Phones
Date: 15 Dec 93 11:44:54 PST
Organization: Medical Laboratory Network; Ventura, CA


Hello,

Some time ago I posted about the problems I had using my Orange
calling card with some privately owned pay phones. Basically, some
phones appeared to be programmed so they would drop the connection
after a certain number of numbers have been punched. When I complained
to one of the operators, I was told that it was to help law
enforcement in the war against drugs (yeah, right ... more like force
you to use their operator $ervice$).

So I called one of the operators today from a payphone that was giving
me that trouble. This time I told her "I had problems using the
voicemail system at work". She suggested to push the keys slower and
to leave a longer pause each two or three keystrokes.

It worked. I dialed the target number leaving three second pauses
between the phone number and the calling card number and waited five
seconds before pushing in the PIN.

Hope it works elsewhere.


Javier Henderson     [email protected]


[Moderator's Note: Interesting theory. If anyone else tries this and
has success (from a phone at which previously they were unable to
continue pressing buttons) please write and let us know.   PAT]

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

From: [email protected] (Paul Coladonato)
Subject: Portable Satellite Phone System
Organization: Hong Kong Internet & Gateway Services Ltd.
Date: Thu, 16 Dec 1993 06:44:08 GMT


Hello all,

Does anyone know if it is currently possible to have a portable
satellite phone system useable anywhere in the world?  That would
allow reliable modem communications from areas poorly served by land
lines?  What companies provide this equipment/services?


Thanks,

Paul

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

From: [email protected] (Bob Smith)
Subject: Digital Phones of the Past
Organization: Computer Sciences Corporation
Date: Wed, 15 Dec 1993 15:32:06 GMT


The term digital phone today seems to be interchangable with ISDN
phone.

However, I seem to recall a time in the past (70s) when a digital
phone had a bunch of digital circuitry in it and talked to a pre-ISDN
digital hook up.

My memory may be failing but I seem to recall DTMF digitized voice and
Bell's DSDS being tied to gether.

Please help staighten out my graying brain!!! Am I on track or is this
an erroneous recollection of an old {Popular Science} article?


Thanks,

bob

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

Subject: Check From AT&T: Here's What to Do!
Date: Wed, 15 Dec 93 23:56:17 CST
From: [email protected] (Robert A. Book)


I got one of those $50 checks from AT&T, and (separately) a $20
"credit voucher" good toward payment of my AT&T Unversal MasterCard
bill with the same conditions (sign it and get switched to AT&T).  I
found a perfectly legal, ethical way to get the face value of the the
voucher, the check, and then some.

My primary carrier is MCI.  I called MCI and told them what I had
received.

For the "credit voucher," they gave me a credit to my account for the
face value ($20), in exchange for my sending them the voucher.

For the check, the told me to write "Void" across the check, and send
it to them, in exchange for which they would send me something called
a "Customer Appreciation Bond" with a face value equal to the value of
the check ($50).  I could either send this check back immediately for
a $50 credit, or hold on to it, in which case it would *gain* $5 per
month every month for up to one year.  I could exchange it at any time
for the total value, which after a year would be $110.

Gee, these guys are getting desparate!  :-)

NOTE: I got the idea to call MCI (which, I admit, I should have
thought of myself) from another posting to this Digest in which
someone with Sprint called them, and they exchanged the check for
face-value credit.  So ...

 ***** THE MORAL OF THE STORY *****

If you receive a check or similar instrument, negotiable on the
condition that you change carriers, and you don't want to change, call
you current carrier.  They will probably match, and in the case of
MCI, beat the offer, to keep you as a customer.  This is a legal,
ethical, and risk-free way to redeem these offers without switching
carriers.


Robert Book  [email protected]

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

Date: Wed, 15 Dec 1993 12:20:00
From: Charles Hoequist <[email protected]>
Subject: Re: New 411 System in Atlanta


In the Digest Issue 772 Les Reeves requested information about the new
411 service in the Atlanta area (it's also now in service in a couple
of other areas in Georgia). Here are some details.

The service is called ADAS (Automated D.A. Service). It does not use
any voice recognition, just store and and playback. Its virtues are
(1) saves telco money, because the front end of the call (querying
city and listing) is automated and so not occupying an operator
position; (2) saves operators from having to say, "This is <name>,
what city?" 1000-1200 times a shift (which is the average range).  (3)
increases throughput by discouraging callers who either just want to
abuse an operator or want something other than DA (I listened to a
couple of hours of recordings from an operator position, and I was
amazed at the variety of information requests that came in).

As Les noted, the application prompts for city name and listing name,
then (if everything works right), a subscriber hears the Automatic
Response Unit giving the desired number. From the operator's
perspective, there is first a special tone announcing the arrival of
an ADAS call, then the recorded city name, then the recorded listing
name (i.e.  what the subscriber said in response to the prompts).  If
the recordings aren't satisfactory, the operator opens a call path to
the subscriber and collects the information, but this is infrequent.
Normally, the operator does the database search and hands the call off
to the ARU.

Hope this helps.


Charles Hoequist, Jr.   | Internet: [email protected]
BNR, Inc.               |  voice: 919-991-8642
PO Box 13478            |  fax:   919-991-8008
Research Triangle Park NC 27709-3478

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

From: [email protected] (danny burstein)
Subject: Re: Double Hunt Group - Possible?
Date: 16 Dec 1993 01:38:42 -0500
Organization: PANIX Public Access Internet and Unix, NYC


While Pat explained the process, he was a bit, ahem, wordy. So to clear
this up in just a few paragraphs:

Problem: Customer has a mix of computer modems and lines, wants to
rearrange them so that hi-speed callers (who presumably pay extra) get
high speed modems, but low speed folk get the low speed. He also wants
teh high speed folk to kcik into the low speed modems when all high
speed are busy.

<note: I'd suggest just having them busy out, but that's personal choice>

Solution:

(Bear in mind that the numbers you get will -not- be sequential, nor
need even be in ascenidng order, but I'm writing them this way to
simplify matters.)

You currently have a hunt group with 25 lines, with the numbers
starting at xxx-y101 and going to xxx-y125. You only "give out" the
main number, xxx-y101 and when that's busy, calls hunt over to y102,
y103 ... y125.

What you should do now is get an additional ten numbers (or, perhaps,
exchange the xxx-y116-y125 ones) in the sequence:

 xxx-y091 -> xxx-y100. These ten numbers/lines should be hooked up to
'hunt' as well, and when all are busy, should continue the hunt into
the old numbers, xxx-y101.

 You give out the super secret high speed main number xxx-y091 to
your extra value customers, and do NOT give it out to the low speed
folk.

 For good measure, you might also get an additional line xxx-y090
which you give out to NOBODY except yourself for dial-in.

 So, again, you will now have the following:

 xxx-y090   <- super secret number known only to you

 xxx-y091   <- start of hi speed hunt sequence *
 xxx-y092
    ...    <- the hunt sequence for hi speed
 xxx-y100

 xxx-y101 <- start of low speed hunt **
 xxx-y102
    ...
 xxx-y125 <- end of low speed hunt

* is the high speed start, you give out this number to your valued cust-
omers.

** is low speed start (-and- is hunted over when high speeds are busy).


[email protected] adds: all the usual disclaimers regarding liability,
intelligence, accuracy apply. spelling disclaimer is doubled.

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

Date: Wed, 15 Dec 93 10:42 EST
From: [email protected] (John R Levine)
Subject: Re: Ethernet Over Laser Link
Organization: I.E.C.C.


Bob Lummis ([email protected]) wrote:

> I am looking for a way to send Ethernet across a public street. Somebody
> told me there is a $2500 pair of laser devices that can do that. Another
> person in this newsgroup said $5,000 but gave no brand names. I know of the
> LCI brand of device that costs more like $15,000 per link (both ends).

I'm surprised that nobody's mentioned NCR Wavelan.  It's a 2 mb/sec
wireless Ethernet that uses 900 MHz spread spectrum transmission.
It's good up to about 300 feet with the included omnidirectional
antennas, several miles line of sight with outdoor yagis.  They're
really cheap, list price $800 per node, dealer price about $600.  (NCR
sells only to distributors who in turn sell only to dealers; I found
that the easiest way to get my hands on them was to become a dealer.)
For the security minded, there's an optional link-level DES encryption
chip, though it's pretty hard to intercept already unless you know
which of the 50,000 possible scrambling codes a particular network is
using.

The main complaint is that they're packaged as ISA or MCA cards to be
plugged into your PC, so if you use any other kind of computer, you
lose.  On the other hand, at that price, you can throw in an old 286
PC and a generic Ethernet card, run PCROUTE or PCBRIDGE, and still
have an Ethernet bridge or router for $1000 per end.  I use a pair
with PC route to connect my home Ethernet to the Internet.  At 300
feet, it works adequately (except when it's raining heavily) but if I
ever get around to installing the outside antennae, the rain problem
should go away.

If you call NCR headquarters in Dayton OH, there's a guy there who can
send you some information.  If you can't find a dealer and don't want
to become one, I suppose you could buy them through me.

Regards,

John Levine, [email protected], {spdcc|ima|world}!iecc!johnl

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

Subject: Re: Computer Cannot Receive From Modem
From: [email protected] (Arthur Rubin)
Date: 15 Dec 93 18:17:40 GMT
Organization: Beckman Instruments, Inc.


In <[email protected]> [email protected] writes:

> I just purchased a new computer.  I have 2400 baud modem and cable
> that works just great with my old computer.  With the new one, the
> computer can send to the modem fine, but cannot receive anything from
> the modem.  For example, the computer tells the modem to dial a
> number, the modem does, carrier *is* detected (per the modem light),
> but the program never detects anything being sent by the modem.  (Echo
> does not work at all either).

You may be able to solve the problem with software.  It is possible
that the "connect" line is not connected to the card, so your computer
is assuming that there is no data, but that software can override.

Also, I've discovered that modem cables are not quite standardized.
Check the manual for your modem and computer to see if you need a
non-standard cable to connect the two.

(Posting this on the newsgroup/forum for your specific computer and/or
modem may be more helpful.)


Arthur L. Rubin: [email protected] (work) Beckman Instruments/Brea
[email protected] [email protected] [email protected] (personal)
My opinions are my own, and do not represent those of my employer.

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

From: [email protected] (Jay Hennigan)
Subject: Re: Computer Cannot Receive From Modem
Date: 16 Dec 1993 20:50:03 -0800
Organization: Regional Access Information Network (RAIN)


In article <[email protected]> [email protected] (David
Gast) writes:

> I just purchased a new computer.  I have 2400 baud modem and cable
> that works just great with my old computer.  With the new one, the
> computer can send to the modem fine, but cannot receive anything from
> the modem.  For example, the computer tells the modem to dial a
> number, the modem does, carrier *is* detected (per the modem light),
> but the program never detects anything being sent by the modem.  (Echo
> does not work at all either).

> Unfortunately, the I/O card does not appear, at least according to the
> instruction manual, to have any dip switches.

> Any ideas what I need to do?  Get a new card?

You'll probably wind up getting a new card, but you can find out for
sure by making a simple loopback adapter from a DB-25 connector that
plugs into the card.  Connect together pins 2 and 3.  Also connect
together pins 4 and 5, and lastly connect together pins 6, 8 and 20.
Plug this into the card and you should get echo.  If so, the card is
probably OK and the trouble is in the modem or cable.  A similar
connector of the opposite gender can be plugged into the modem.  If it
is set to auto-answer, then an incoming caller will get echo if the
modem is OK.  The pin 2-3 jumper loops the transmitted and received
data.  The 4-5 and 6-8-20 jumpers may or may not be required, and are
used in some cases for "handshaking" signals between the computer and
modem so that each device can determine if the other is present and
ready.

From your description of the problem, it sounds as if the card is
defective.

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

Date: Wed, 15 Dec 1993 11:16:00 -0500
From: [email protected] (Mark Brader)
Subject: Re: NPA 905 Not Universally Recognized


David Esan ([email protected]) writes:

> The 905 NPA went live on 15 October, the pages were not filed until
> 22 November. ... sloppy work on the part of BellCore. ...

Even worse.  The official date for 905 was actually October 4.

I just did some experiments with a friend in area code 905 who is a
local call away from me here in 416.  As expected, he can still reach
me by dialing NXX-XXXX or 416-NXX-XXXX.  If he tries 905-NXX-XXXX,
which is wrong, the recording he gets says "The number you have dialed
is a 10-digit local number.  Please dial 416 plus NXX-XXXX" -- which
is right, but maybe a bit confusing.  As noted previously, Call Return
here announces the last number that called you before giving you the
option to return the call, and it has always given the area code.  His
calls to me are still given as being from 416, irrespective of which
way he dials.

Similarly, I can dial his number as NXX-XXXX or 905-NXX-XXXX.  If I
try 416-NXX-XXXX, I get fast busy (reorder).  I tried a number that is
in 416; I can dial it as NXX-XXXX or 416-NXX-XXXX.  If I try 905-NXX-XXXX,
I get a "cannot be completed as dialed" recording.

In the days when 905 and other codes reached Mexico, how many digits
had to be dialed after the pseudo area code?  Our Moderator thinks
that a couple of years out of use is sufficiently long to avoid a
serious nuisance of wrong-language wrong-number calls; I think he
underestimates the number of people who do things like putting an
obsolete code on business stationery or writing down a number and
calling it years later.  But if these calls will fail to complete
anyway, no problem.

Was the answer different for different pseudo area codes?


Mark Brader   SoftQuad Inc., Toronto  utzoo!sq!msb, [email protected]


[Moderator's Note: Actually, there were the same number of digits;
they were just parsed differently. And the did not refer to it as
an 'area code', but rather, an 'access code' (I think). What we
actually dialed was '90' plus a 5 then the number in Mexico City
if my memory is correct.  PAT]

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