30 Years of the Digest ... founded August 21, 1981
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The Telecom Digest for November 4, 2011
Volume 30 : Issue 281 : "text" Format
====== 30 years of TELECOM Digest -- Founded August 21, 1981 ======
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Telecom and VOIP (Voice over Internet Protocol) Digest for the
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See the bottom of this issue for subscription and archive details
and the name of our lawyer, and other stuff of interest.
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Date: 03 Nov 2011 05:21:55 GMT
From: Doug McIntyre <merlyn@geeks.org>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Standard Telephone Wire
Message-ID: <4eb224f3$0$74947$8046368a@newsreader.iphouse.net>
fatkinson.remove-this@and-this-too.mishmash.com writes:
> Can anyone recommend an outlet that still sells standard telephone wire?
> I am looking for a one thousand foot roll of plenum four conductor
>(or more) and I may need it fast.
> Everyone I call wants to sell me CAT-3 or CAT-5E which is more
>expensive.
I guess to me, "standard" phone wire existed before Plenum jackets, so
right away you are asking for "new fangled stuff".
Plenum is the expensive part. Not if it is Cat3 or Cat5e vs. what you
are looking for which is "voice-grade" in the industry (or Cat1, but
nobody calls it that). Generally, the old school 4 wire phone cable
doesn't come in plenum jacket, and only the home centers carry it,
no contractor uses 4-wire phone cord.
Last time I priced things out, Cat3 plenum was nominally more
expensive than voice-grade plenum. Like maybe $10 a reel.
cat5e and cat3 are pretty close in price, maybe ~$50 a box. If there
is any possibility of VoIP in the future, paying $50 a box premium
compared to $90/hour labor for the electrician to repull things is
pretty cheap insurance.
You should be able to get bulk cable at Home Depot/Lowes at fairly
decently pricing compared to what you'd expect a big-box to charge.
Otherwise, the major distributers like Graybar, Anixter, Allied.
Or secondary ones like Digikey, Newark, Blackbox, etc.
Also, you won't find too much definitive pricing online because the
market for copper is highly variable. Each shipment in will be a
different cost to the vendor, so they are all going to do
request-for-quote type sales on cables (or price it high enough to
cover the ups and downs, so those aren't the ones you want to deal with).
Date: Thu, 3 Nov 2011 09:37:52 -0400
From: Telecom Digest Moderator <redacted@invalid.telecom.csail.mit.edu>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Cable's monopoly in data communications
Message-ID: <20111103133752.GA7333@telecom.csail.mit.edu>
If you do nothing else today, read this article in the Harvard Law
Review Journal: I got the link from the Cybertelecom-l mailing list.
Susan P. Crawford has written an article entitled "The Communications
Crisis in America", in which she eloguently debunks the myth of
competition in the transport of data to American consumers.
Here's just one memorable quote:
The industry is poised to reap the central reward for geographical
clustering, upgrades, and de facto monopoly presence -
unconstrained pricing ability and an unmatched high-speed
communications service in a marketplace where consumers are
agitating for higherspeed communications and the cable companies
are making north of 90% margins on their data services.
http://hlpronline.com/wp-content/uploads/2011/07/Crawford.pdf
--
Bill Horne
Moderator
Date: Thu, 3 Nov 2011 04:41:05 +0000 (UTC)
From: moroney@world.std.spaamtrap.com (Michael Moroney)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Air Raid sirens
Message-ID: <j8t611$nkg$1@pcls6.std.com>
HAncock4 <withheld@invalid.telecom-digest.org> writes:
>As an aside, Bell Labs did a lot of research in sirens during WW II
>for air raid defense purposes. They wanted to develop warnings loud
>enough to be heard within buildings of the city. Apparently they were
>successful. I've heard (unconfirmed) some sirens were so powerful
>that hearing damage resulted.
Umm, yeah. Some of the air raid sirens were powered by V8 car engines!
I've heard stories that bits of paper immediately in front of the
horn could be set on fire, but since then I've heard that was an
exaggeration/urban legend.
Date: Thu, 03 Nov 2011 05:39:58 -0400
From: Carl Navarro <cnavarro@wcnet.org>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Standard Telephone Wire
Message-ID: <i6o4b7hoa9t4p37003sj5e9pf4krs8gddg@4ax.com>
On Wed, 2 Nov 2011 16:30:04 -0600,
fatkinson.remove-this@and-this-too.mishmash.com wrote:
> Can anyone recommend an outlet that still sells standard telephone wire?
>
> I am looking for a one thousand foot roll of plenum four conductor
>(or more) and I may need it fast.
> Everyone I call wants to sell me CAT-3 or CAT-5E which is more
>expensive.
> Regards,
Define expensive. Back in the day, we actually used to stock Cat-3
Plenum because it was about the same price as Cat-5 PVC. Today, I
can't even think of the last time I really bought the stuff....a quick
price check shows about $140 a thousand for 3 Plenum and we pay around
$200 for 5e Plenum.
hardly worth stocking 2 types of cable.
Carl
Date: Thu, 03 Nov 2011 03:57:20 -0500
From: bonomi@host122.r-bonomi.com (Robert Bonomi)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Telephony on TV
Message-ID: <8_2dnZ7AT8Ltyi_TnZ2dnUVZ_sadnZ2d@posted.nuvoxcommunications>
In article <731c17e4-45f1-467d-83ce-dc5786b8aa65@j20g2000vby.googlegroups.com>,
HAncock4 <withheld@invalid.telecom-digest.org> wrote:
>On Nov 2, 6:09 pm, bon...@host122.r-bonomi.com (Robert Bonomi) wrote:
>
> Given that, and the general state of
>PBX technology of that era, I don't think there was a way a dialed
>call could've been easily traced, especially after the fact (if
>that's what they did.)
>I think in TV/movies they took a lot of liberties on the concept of
>'tracing a call'.
>
>In Three Days of the Condor, they showed a CIA office where supposedly
>a map came up on a screen showing the location of an originated call.
>_If_ the originating exchange had ANI (and not all did in 1976) that
>kind of technology was theorectically possible, but it would require
>a sizable mainframe to handle the database and the digitization of
>geographic information not often done back then, plus some nice
>hardware to select the map panel and display it.
Sorry, but you "don't know what you don't know" in that respect.
The display technology shown actually existed, and did not involve
any digitization of data. Typically driven by something on the scale
of a PDP-8 to a PDP-11/03.
>As an aside, they looked like Hagstrom street maps on the display.
>Hagstrom was a long time top map maker for the NYC area.
No kidding. :)
It was simple optical projection of film images (probably micro-fiche)
data, with stepper-motor-driven X-Y axis positioning. It used a simple
3-coordinate system -- film #, and X-Y values -- to represent any
displayable point in the system.
Very similar to the technology employed in the terminals invented by
The University of Illinois, for their PLATO system.
Aside, ANI wasn't necessary for identifying a calling number, and was
not being used in the purported CIA 'trace' facility. If that trace
was ANI-based, they'd have the calling number before answering the phone.
With electro-mechanical C.O. switches one had to have a tech physically
track the connection through the relays.
With computer-driven control components, a trace needs only remote access
to the switch console, to match the incoming circuit to the outgoing one.
then on to the 'upstream' switch, and repeat. The limiting factor on how
fast you can trace is simply how fast you can access the switches involved.
Before SS7 -- and I believe there is still such a capability in SS7 -- there
was a capability for a telco to issue a command for the switches handling
a call to 'freeze' the connection, such that the circuit was not torn down
when either party hung up. This eliminated the need to 'keep the caller
on the line' until the trace was completed. This was a "lock and trace"
operation.
Date: Fri, 04 Nov 2011 08:26:34 +1100
From: David Clayton <dcstarbox-usenet@yahoo.com.au>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Telephony on TV
Message-ID: <pan.2011.11.03.21.26.28.738219@yahoo.com.au>
Just watched another classic Hawaii 5-O episode where they tracked down
kidnappers by setting up a call to a public phone and then cut to an
exchange where they showed someone looking at SxS switch equipment and
backtracking the call rack by rack to a piece of jumper wire on the MDF.
Instead of just the info of a trace being delivered as a plot piece, they
basically showed the process (I don't know how accurate the depiction was,
but it looked good to me), very impressive!
I am beginning to suspect whoever they had writing in that old season 3
either knew a bit about the phone system or they had a consultant who did.
--
Regards, David.
David Clayton
Melbourne, Victoria, Australia.
Knowledge is a measure of how many answers you have, intelligence is a
measure of how many questions you have.
***** Moderator's Note *****
They just did it because SxS looks cool. However fantasic the film
might seem to techies such as we, let's remember that to the ordinary
public it was marvelous and mysterious.
I bet you guys talk back to the screen in movies, too.
Bill Horne
Moderator
Date: Thu, 3 Nov 2011 15:50:03 +0000 (UTC)
From: "Adam H. Kerman" <ahk@chinet.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Telephony on TV
Message-ID: <j8ud7b$4f4$1@news.albasani.net>
Robert Bonomi <bonomi@host122.r-bonomi.com> wrote:
>HAncock4 <withheld@invalid.telecom-digest.org> wrote:
>>I think in TV/movies they took a lot of liberties on the concept of
>>'tracing a call'.
>>In Three Days of the Condor, they showed a CIA office where supposedly
>>a map came up on a screen showing the location of an originated call.
>>_If_ the originating exchange had ANI (and not all did in 1976) that
>>kind of technology was theorectically possible, but it would require
>>a sizable mainframe to handle the database and the digitization of
>>geographic information not often done back then, plus some nice
>>hardware to select the map panel and display it.
>Sorry, but you "don't know what you don't know" in that respect.
All right, Robert. As always, you know better, but don't offer an
explanation. Hancock has used this example a number of times in the past
on Usenet.
>The display technology shown actually existed, and did not involve
>any digitization of data. Typically driven by something on the scale
>of a PDP-8 to a PDP-11/03.
If the map isn't digitized (I assume you mean in a GIS sense), then there
has to be a database of origin points for each street segment from a
given intersection, plus points at which a street changed direction
between intersections, as well as a ratio between house number increment
approximations and how far to move the image. For coordinates, you'd need
to know the house numbers of the intersections themselves. Plus you'd
require some logic to resolve conflicts of two streets with multiple
intersections.
This could have been done at the time with a hell of a lot of data input.
The Census Bureau began the process of mapmaking from DIME based on
the 1960 census, which was used until TIGER was built based on the 1980
census. DIME maps were attrocious. Intersections lined up on one end
but not the other, and they weren't made human-readable by cartographers.
Did they have the ability to relate locations to commercial maps of the
era? Again, with a lot of additional data input, it probably could have
been done, but I doubt the results would have been as satisfactory as
what we saw on screen.
DIME map making did use USGS topographic maps as their base. Regardless,
DIME maps looked nothing like topo maps.
This was all part of a process that led to associating addresses with
block-level data, ZIP+4 codes so that future censuses could rely more
heavily on mailed-in results, and assignment of Census blocks to
latitude/longitude coordinates, the result of which was lots of targeted
marketing thanks to vastly improved demographic data mostly paid for
by taxpayers.
I agree with hancock that what we saw on screen in that movie was somewhat
fantastic.
>>As an aside, they looked like Hagstrom street maps on the display.
>>Hagstrom was a long time top map maker for the NYC area.
>No kidding. :)
>It was simple optical projection of film images (probably micro-fiche)
>data, with stepper-motor-driven X-Y axis positioning. It used a simple
>3-coordinate system -- film #, and X-Y values -- to represent any
>displayable point in the system.
It had to be more than that, for each intersection needed an association
between the map's coordinates and the street addresses of each intersection.
Then you'd need to know what angle the street was on as a tangent originating
from that intersection plus how many feet an address increment represented.
Date: Thu, 3 Nov 2011 08:18:59 -0700 (PDT)
From: HAncock4 <withheld@invalid.telecom-digest.org>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Telephony on TV
Message-ID: <c674ed6b-bb74-4565-bdcd-fde3559d58a5@o19g2000vbk.googlegroups.com>
On Nov 3, 4:57 am, bon...@host122.r-bonomi.com (Robert Bonomi) wrote:
> >In Three Days of the Condor, they showed a CIA office where supposedly
> >a map came up on a screen showing the location of an originated call.
> >_If_ the originating exchange had ANI (and not all did in 1976) that
> >kind of technology was theorectically possible, but it would require
> >a sizable mainframe to handle the database and the digitization of
> >geographic information not often done back then, plus some nice
> >hardware to select the map panel and display it.
>
> Sorry, but you "don't know what you don't know" in that respect.
>
> The display technology shown actually existed, and did not involve
> any digitization of data. Typically driven by something on the scale
> of a PDP-8 to a PDP-11/03.
> It was simple optical projection of film images (probably micro-fiche)
> data, with stepper-motor-driven X-Y axis positioning. It used a simple
> 3-coordinate system -- film #, and X-Y values -- to represent any
> displayable point in the system.
The mechanical part of automatically selecting and displaying a
microfiche is not that hard.
I suggest that _in that era_ the real-time translation of a phone
number to a street address and then street address to a specific fiche
frame would have been a technical challenge. Doable, but not easy nor
cheap.
First, they would need dynamic information from the phone company of
the physical address associated with every telephone number in the
metropolitan region. In those days there was a high volume of service
changes. Due to the high volume, the telephone company itself had
trouble maintaining that information accurately and that was a
contributing factor toward the service crisis of that era. So,
maintaining a separate accurate database would have been a big
challenge.
Secondly, they would need to translate a specific street address to
the proper map location for the entire metro area and keep that up to
date and accurate. I'm not sure computerized databases of that sort
of thing existed back then(remember, we're covering both the city and
suburbs in three states down to the house level). It could've been
created of course, but that would be a big job since so much of it
would be done by hand.
As an aside, in the old days many addresses were shown as
intersections eg "Fifth & Main Streets". while today many addresses
are shown with a street number, eg "3 Fifth Street". I suspect that
change is due to making it easier to have computerized databases for
public safety and the post office.
> Very similar to the technology employed in the terminals invented by
> The University of Illinois, for their PLATO system.
>
> Aside, ANI wasn't necessary for identifying a calling number, and was
> not being used in the purported CIA 'trace' facility. If that trace
> was ANI-based, they'd have the calling number before answering the phone.
If they didn't use ANI, what did they use to identify the calling
number quickly as shown in the movie?
> With electro-mechanical C.O. switches one had to have a tech physically
> track the connection through the relays.
> With computer-driven control components, a trace needs only remote access
> to the switch console, to match the incoming circuit to the outgoing one.
> then on to the 'upstream' switch, and repeat. The limiting factor on how
> fast you can trace is simply how fast you can access the switches involved.
Most exchanges in 1976 were electro-mechanical of all three types. A
few exchanges were independent with very basic switches, such as on
Fisher's Island.
I believe ANI was fairly widespread back then, but I know from
personal experience that not all city exchanges had it and still
depended on ONI.
Of course, special trunks and arrangements would be required from all
exchanges or tandem offices to the CIA office in order to pass through
the calling number. Doable, but not cheap in those days. (The CIA
wasn't supposed to be meddling in domestic affairs, that was the FBI's
job. But we can assume that the CIA got whatever it wanted from the
phone company as long as money changed hands to cover the cost.)
> Before SS7 -- and I believe there is still such a capability in SS7 -
> there was a capability for a telco to issue a command for the
> switches handling a call to 'freeze' the connection, such that the
> circuit was not torn down when either party hung up. This
> eliminated the need to 'keep the caller on the line' until the trace
> was completed. This was a "lock and trace" operation.
I believe a feature in the early 911 systems was the ability for the
911 operator to seize the circuit and ring back the caller if he hung
up.
As an aside, in the movie Redford tracked a phone number to area code
202 and the CIA. But the CIA was in Langley VA, so wouldn't their
area code be the one for Virginia? Likewise, when he tracked a call
to the rouge manager at his suburban home, wouldn't he have had a
different area code? I suspect the movie just used some dramatic
license for that (as they did in the central office scenes).
***** Moderator's Note *****
Um, you do realize that the voice of HAL didn't come from a computer,
right?
Is there any question in your mind that Dustin Hoffman and Robert
Redford were not the reporters who broke the Watergate Coverup story?
OK, here's a trick question: can you accept that "Bedtime for Bonzo"
was not filmed in the OVal Office of the White House?
This thread has wandered into a discussion of how many angels can fit
in the heart of a Hollywood agent, so it's time to close it.
Bill Horne
Moderator
Date: 3 Nov 2011 15:10:26 -0400
From: kludge@panix.com (Scott Dorsey)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: 60 hz as a time standard
Message-ID: <j8uov2$sc3$1@panix2.panix.com>
Geoffrey Welsh <gwelsh@spamcop.net> wrote:
>Garrett Wollman wrote:
>
>> You probably saw an episode of the PBS series "History Detectives".
>> The plan was not to alter the power line frequency, but to superimpose
>> an RF signal on the line that would activate an alarm that was plugged
>> into a household outlet. The device worked, but the plan did not, [...]
>
>It worked? Surely an RF signal would not pass a transformer designed to
>work optimally around 60 Hz? Or should "RF" be interpreted liberally here?
Some of it does, due to interwinding capacitance between the primary and
secondary. It is also possible to put shunt caps around the transformer
to make it easier to pass the signals (or active repeaters).
The same concept is being promoted today as BPL, although the BPL people are
trying to get far more bandwidth at far higher frequencies (with pretty
awful RFI consequences).
Carrier current transmissions, though, are still very popular for low
bandwidth low frequency RF applications, and the power companies often use
them for carrying signalling data.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Date: Thu, 3 Nov 2011 11:41:18 -0400
From: Monty Solomon <monty@roscom.com>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Apple Concedes iPhone, iPad Battery Problem
Message-ID: <p06240826cad8666a98ce@[10.0.1.3]>
Apple Concedes iPhone, iPad Battery Problem
By IAN SHERR
NOVEMBER 3, 2011
Apple Inc. acknowledged that customers have experienced disappointing
battery life on some of its devices, and said it will release a
software update soon to address the issue.
The company attributed the problem to bugs in the latest iteration of
its mobile-device operating system, iOS 5.
...
http://online.wsj.com/article/SB10001424052970203716204577014480264875846.html
Date: Thu, 3 Nov 2011 09:00:34 -0700 (PDT)
From: HAncock4 <withheld@invalid.telecom-digest.org>
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Standard Telephone Wire
Message-ID: <80395d82-c446-4249-90b7-8e9454071400@x2g2000vbd.googlegroups.com>
On Nov 2, 6:30 pm, fatkinson.remove-t...@and-this-too.mishmash.com
wrote:
> Can anyone recommend an outlet that still sells standard telephone
> wire?
I did a search on google for "D Station wire" and a number of vendors
came up. Whether they are any good I have no idea, but it's worth
checking.
Date: 3 Nov 2011 15:13:06 -0400
From: kludge@panix.com (Scott Dorsey)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Standard Telephone Wire
Message-ID: <j8up42$aov$1@panix2.panix.com>
<fatkinson.remove-this@and-this-too.mishmash.com> wrote:
> Can anyone recommend an outlet that still sells standard telephone wire?
>
> I am looking for a one thousand foot roll of plenum four conductor
>(or more) and I may need it fast.
>
> Everyone I call wants to sell me CAT-3 or CAT-5E which is more
>expensive.
Cat-3 is standard telephone wire.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Date: Thu, 3 Nov 2011 17:03:57 -0700
From: dplatt@radagast.org (Dave Platt)
To: telecomdigestmoderator.remove-this@and-this-too.telecom-digest.org.
Subject: Re: Standard Telephone Wire
Message-ID: <dombo8-1do.ln1@radagast.org>
In article <j8up42$aov$1@panix2.panix.com>,
Scott Dorsey <kludge@panix.com> wrote:
>> Everyone I call wants to sell me CAT-3 or CAT-5E which is more
>>expensive.
>
>Cat-3 is standard telephone wire.
These days, as far as new wiring is concerned, I'd generally agree. I
don't see much sense in pulling anything less than Cat-3 for any new
installs.
The older standard telephone "station cable" is far from Cat-3
quality... its conductors are not twisted into pairs, and I don't
believe it's defined with any particular characteristic impedance.
I grab chunks of it whenever I can, at surplus stores and swap-meets.
Not for wiring... I won't use it for that... but to strip down into
the individual conductors, which my wife finds to be just the right
size and stiffness for some of her art projects.
--
Dave Platt <dplatt@radagast.org> AE6EO
Friends of Jade Warrior home page:
http://www.radagast.org/jade-warrior
I do not wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!
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