How to busy a phone line (POTS 2 wire)
Gregory B. Newby
few that are flakey yet. I have 32 dial-in lines on our campus
centrex in a hunt group.
What I'd like is to be make the incoming telephone lines hooked up to
non-functioning modems be "busy" (that is, "off hook") until the
modems are fixed. This will have the effect of preventing
dial-in-ers from getting the broken modems.
I know I can call my telecom office, and have them do this at
their switch (or however they do it). But what I'd like is
a simple do-dad, connector, or whatever so that I can do it
myself. (Preferably, NOT involving hooking up a regular
telephone and taking it off the hook!). I can work with
either the male or female end of the modular jack.
My assumption is that I just need to short, ground, or add a
resistor to the wires somewhere.... but I obviously don't know
much!
Thanks for any guidance you might offer.
-- Greg Newby
/* Gregory B. Newby, Assistant Professor in the Graduate School of Library */
/* and Information Science, University of Illinois at Urbana-Champaign */
/* 501 E. Daniel Street, Champaign IL, 61820-6212. Voice: 217-244-7365 */
/* Fax: 217-244-3302. Email: gbn...@uiuc.edu, gne...@ncsa.uiuc.edu */
==== Try Prairienet. Telnet to firefly.prairienet.org, login 'visitor' ====
mikem
In any case, the worst that could go wrong is that the resistor could
burn up.
Wil Dixon
Greg,
According to a recent News Gazette article you are the Graduate
School of Library Science's technical Guru! Try a 600 ohm resistor
across the line.
Wil
--
/-----------Wil Dixon------------\ |~~\_____/~~\__ |
| wild...@uiuc.edu 217-244-1321 |___________ \N1____====== )-+
| University of Illinois | ~~~|/~~ |
Ted Dunning
Try putting an 8-10 ohm resistor (rated 2 watts or more) across it.
BIG mistake here.
try 600 ohms instead.
Tomi H Engdahl
> Try putting an 8-10 ohm resistor (rated 2 watts or more) across it.
>BIG mistake here.
>try 600 ohms instead.
Mistake here also. 600 ohm is the AC impedance of telephone
transformer. The DC resistance is normally around 200-400 ohm.
--
========== Tomi.E...@hut.fi ====== Then of Braiwash Inc. ===========
"This text is provided "as is" without any express or implied warranty"
The 1st Noel
: What I'd like is to be make the incoming telephone lines hooked up to
: non-functioning modems be "busy" (that is, "off hook") until the
: modems are fixed. This will have the effect of preventing
: dial-in-ers from getting the broken modems.
just short out the red and green.... that is what I have alwayz done..
- Noel..
Kevin Ruddy
probably want to make a few of them and packing them into RJ11s. Or can you
buy them premade?
---
Kevin Ruddy | Network Management Group | Equipment Division | Raytheon Company
------------+--------------------------+--------------------+-----------------
DISCLAIMER: This message is my personal opinion and not that of my employer.
John E. Lundgren
This is a BIG mistake to say that is a BIG mistake.
The phone line from the CO has several hundred ohms resistance already.
Putting a ten ohm or 600 ohm resistor across it is NOT going to make any
appreciable difference. Yup. No appreciable difference.
So just go with the flow and put a connector with the green and red wires
shorted together into the modular plug.
The resistor idea is perfectly fine BUT...
It's more expensive and it's really hard to get a connector to crimp
onto solid wire. The connections tend to be intermittent.
The resistors dissipate heat, and in a lightning storm (or any other time
when there's a fault on the phone line) they tend to burn up.
--
$$$$$$ John Lundgren $$$$$$ jlu...@eis.calstate.edu $$$$$$
$$$$$$ jlun...@pop.rancho.cc.ca.us $$$$$$ Standard Disclaimers apply.
Rancho Santiago College - 17th St. at Bristol - Santa Ana, CA 92706
$$$$$$ Two rights don't make a wrong, they make an airplane. $$$$$$
$$$$$ "The man who toys with the most dies, wins." - Dr. Kevorkian? $$$$$
John Lundgren
mikem (mi...@sashimi.wwa.com) wrote:
: Try putting an 8-10 ohm resistor (rated 2 watts or more) across it.
: In any case, the worst that could go wrong is that the resistor could
: burn up.
:
I just utterly fail to see the point of putting a resistor this low in
value across the phone line. #24 wire has something like 16 ohms per
KFt, or about 32 ohms per pair KFt.
Most subscriber loops are from a few to tens of Kfeet in length.
According to the Phone FAQ from the Telecom Archives, the subscriber
loops vary from 150 to 400 ohms. I'm not sure if that includes the
relays or inductors at the CO. But this is a current loop, and what
resistance that goes on the end isn't going to make any difference.
So if yous guys just have to insist on putting a resistor on the line to
busy it out, _please_ explain in detail the justification behind this.
--
=====================================================================
| John Lundgren - Elec Tech - Info Tech Svcs | Standard |
| Rancho Santiago Community College District | disclaim- |
| 17th St. at Bristol \ Santa Ana, CA 92706 | ers apply.|
| jlun...@pop.rancho.cc.ca.us\jlu...@eis.calstate.edu | |
=====================================================================
Ken Pizzini
John E. Lundgren <jlu...@eis.calstate.edu> wrote:
>It's more expensive and it's really hard to get a connector to crimp
>onto solid wire. The connections tend to be intermittent.
There are two varieties of connectors: one designed for stranded wire
and one designed for solid wire.
--Ken Pizzini
Mark Miller
Tomi H Engdahl <th...@snakemail.hut.fi> wrote:
>In article <TED.94Au...@lole.crl.nmsu.edu> t...@crl.nmsu.edu (Ted Dunning) writes:
>
>>BIG mistake here.
>>try 600 ohms instead.
>
>Mistake here also. 600 ohm is the AC impedance of telephone
>transformer. The DC resistance is normally around 200-400 ohm.
The DC resistance of my telephone transformer is about 100 ohms.
However, the idea here is to consume as little power as possible ( and
create the least heat. )
I have taken my phone off hook (tested by dialing up on another line )
with a resistor as big as 6600 ohms ( two 3.3 K in series ). I live 3/4
mile in a straight shot from the central office. This consumes the
least TOTAL power. ( 0.32 Watts local heat, 0.38 Watts total )
My phone line has a series resistance of approx 800 ohms (calculated by
interpolation ) and an open circuit voltage of 52.0 V DC. If you use a
resistor in this range you will maximize total power transfer and create
the most heat on you end. (Approx 0.85 Watts local heat, 1.69 Watts total).
Ironically if you use a 100 ohm resistor you will only generate 0.33 Watts
of local heat, despite carrying much larger currents and dissapating 3.0 watts
total.
My recommendation is to use either a large ( > 3K ) or small ( < 220 ohms)
1/2 watt resistor to generate the least local heat. A 1 K resistor gets
quite hot very quickly.
If you short the lines together, most phone systems will shut your line
down and poll it every several minutes before they bring it back up again.
- Mark.
Rahul Dhesi
>10 ohms is way too small. 1000 ohms will work quite nicely and it won't be
>a fire hazard either. If you are a long way away from your central office,
>you might have to go as low as 600 ohms.
I normally use a zero-ohm resistor.
It may seem surprising, but the power dissipation of a zero-ohm
resistor turns out to be very small. The reason being that power
equals resistance times current squared, and resistance is zero.
(Well, close to zero).
For this reason, I can use low-wattage zero-ohm resistors. I just make
them as needed out of 24-gauge cross-connect wire. I take a piece of
it, make a U-bend in it, put the two ends together into the middle of a
6-position 4-conductor modular plug, clamp it in my handy crimper, and
voila! I have a convenient zero-ohm busy-out modular plug.
Due to the low wattage involved, I have not found the need to invest in
the more expensive wire-wound high-wattage zero-ohm resistors. (If I
were very close to the central office, and the current in the busy-out
plug was infinite or close to infinite, then power dissipation would
might be nonzero. I would have to use a wire-wound high-power
zero-ohm resistor.)
--
Rahul Dhesi <dh...@rahul.net>
also: dh...@cirrus.com
Jay Summet
say "busy the line out". There are two ways of doing this:
1. Take your phone, pick up the handset (Press TALK or whatever to get
the dialtone) and walk away.
2. Place a 100-400 ohm resistor accross the line.
Method 1 makes some noise, but is simple.
Method 2 does not make noise, but takes some soldering. (Nobody, but
NOBODY twists the wires!)
If you want to, you can buy a device called a "external hold switch" from
many places which is just a 100-400 ohm resister with a SPST switch and a
LED attached to a RJ-11.
In article <328fil$f...@FERRARI.NMC.ED.RAY.COM>,
Steven Weller
> Due to the low wattage involved, I have not found the need to invest in
> the more expensive wire-wound high-wattage zero-ohm resistors. (If I
> were very close to the central office, and the current in the busy-out
> plug was infinite or close to infinite, then power dissipation would
> might be nonzero. I would have to use a wire-wound high-power
> zero-ohm resistor.)
And you can probably save more money by using a low tolerance
zero ohm resister.
8^)
--
Steven Weller at Windsor Systems +1 502 425 9560 (voice)
2407 Lime Kiln Court, Louisville, KY 40222, USA +1 502 426 3944 (fax)
<OS-9 Consultancy and Software> st...@barefoot.com or swe...@aol.com
Jay Hennigan
>In article <TED.94Au...@lole.crl.nmsu.edu> t...@crl.nmsu.edu (Ted Dunning) writes:
>
>> Try putting an 8-10 ohm resistor (rated 2 watts or more) across it.
>>BIG mistake here.
>>try 600 ohms instead.
>
>Mistake here also. 600 ohm is the AC impedance of telephone
>transformer. The DC resistance is normally around 200-400 ohm.
Just put a short across it. Works fine, hurts nothing. Telephone lines
are current limited by the line relay (or electronic equivalent) in the
central office.
-Jay
David Lesher
>If you short the lines together, most phone systems will shut your line
>down and poll it every several minutes before they bring it back up again.
This seems to have as many lives here as the "Postcards for
Craig Shergold" one in alt.folklore.urban.
Given there is many Kohms of drop, both in the drop, and the line relay
at the CO, how can the CO tell if you have 200, 100 or zero ohms?
The icing on the cake is that people like Floyd with many years in the
telco industry keep repeating "We short it out -- you can too" when
asked. And of course no one has seen the Phone Police kick down a door
to confiscate that dreaded illegal short -- but they know a Friend of a
Friend who has.
Oh well. Say -- Do you collect those pop-top rings?
It will help pay for kidney dialysis.....
--
A host is a host from coast to coast.................wb8foz@nrk.com
& no one will talk to a host that's close...........(v)301 56 LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433
Mark Miller
David Lesher <wb8...@skybridge.scl.cwru.edu> wrote:
>mem...@u.cc.utah.edu (Mark Miller) writes:
>
>>If you short the lines together, most phone systems will shut your line
>>down and poll it every several minutes before they bring it back up again.
>
>This seems to have as many lives here as the "Postcards for
>Craig Shergold" one in alt.folklore.urban.
>
>Given there is many Kohms of drop, both in the drop, and the line relay
>at the CO, how can the CO tell if you have 200, 100 or zero ohms?
>
This is the observed behavior of the phone system here. I have tested it
by shorting the line with an LED in series with it. After a couple of
minutes the LED will turn off. After that the LED will pulse momentarily
every few minutes. When you remove the short the dial tone will return
after the next polling pulse.
I measured the *effective* CO line resistance at 852 ohms, not
"many Kohms" on a dead short. This includes the effective resistance
of the current limiting circuitry in the CO. It is trivial for the CO to
shut down a line temporarily if the current rises above a specified
maximum, although this may only happen if you are near the CO. I live 0.7
miles down the road. This can save the phone company a non-trivial amount
of power. I had 61 ma of short circuit current. That can easily run into
2 to 3 watts of continuous power dissapation in the lines.
- Mark.
mikem
: I just utterly fail to see the point of putting a resistor this low in
: value across the phone line. #24 wire has something like 16 ohms per
: KFt, or about 32 ohms per pair KFt.
: Most subscriber loops are from a few to tens of Kfeet in length.
: According to the Phone FAQ from the Telecom Archives, the subscriber
: loops vary from 150 to 400 ohms. I'm not sure if that includes the
: relays or inductors at the CO. But this is a current loop, and what
: resistance that goes on the end isn't going to make any difference.
: So if yous guys just have to insist on putting a resistor on the line to
: busy it out, _please_ explain in detail the justification behind this.
I suppose I was wrong. It seems that it would be just best to short the
pair.
Floyd Davidson
>In article <THEN.94A...@delta.hut.fi>,
>Tomi H Engdahl <th...@snakemail.hut.fi> wrote:
>>In article <TED.94Au...@lole.crl.nmsu.edu> t...@crl.nmsu.edu (Ted Dunning) writes:
>>
>>>BIG mistake here.
>>>try 600 ohms instead.
>>
>>Mistake here also. 600 ohm is the AC impedance of telephone
>>transformer. The DC resistance is normally around 200-400 ohm.
>
>The DC resistance of my telephone transformer is about 100 ohms.
>
>However, the idea here is to consume as little power as possible ( and
>create the least heat. )
A dead short creates the least heat.
>My recommendation is to use either a large ( > 3K ) or small ( < 220 ohms)
>1/2 watt resistor to generate the least local heat. A 1 K resistor gets
>quite hot very quickly.
>
>If you short the lines together, most phone systems will shut your line
>down and poll it every several minutes before they bring it back up again.
But of course that has nothing to do with the short, it has to do
with the offhook condition and it makes absolutely no difference
whether you made it offhook with a dead short, a telephone, or a
100W 3.002K resistor. The same thing is going to happen in any case.
Telco techs never use anything other than a short to create an
offhook condition when a voice path was not required (if it is,
then a low DC resistance holding coil is used). Telco engineers
design the equipment that way, and subscribers would be well
advised to use the exact same method!
Floyd
--
fl...@ims.alaska.edu A guest on the Institute of Marine Science computer
Salcha, Alaska system at the University of Alaska at Fairbanks.
John Higdon
>This seems to have as many lives here as the "Postcards for
>Craig Shergold" one in alt.folklore.urban.
>
>Given there is many Kohms of drop, both in the drop, and the line relay
>at the CO, how can the CO tell if you have 200, 100 or zero ohms?
Those of us who do real telephony for a living are always amused by the
plethora of nervous nellies who debate the value of the "busy resistor",
when the only concern with any particle of validity (and not much here,
either) is the matter of busying out the line in the first place. I
know of lines all over the country that are busied out with dead
shorts. When the shorts are removed, the service is restored--within
seconds and without any intervention by a repair bureau.
This is the way it works in the real world. As I have said before, I
have an open mind. If someone can produce a single verifiable case of an
intentionally dead-shorted line resulting in any harm whatsoever, it
will be taken under due consideration. Until then, folks, save your
money; save your time; save your aggrevation. Short it out!
>The icing on the cake is that people like Floyd with many years in the
>telco industry keep repeating "We short it out -- you can too" when
>asked.
One of the problems in this society is that people are much more
inclined to believe great sounding theories and folklore rather than
cold, hard experience or first-person knowledge. Never mind how many
years Floyd has worked inside the industry and never mind the many
years of observation the rest of us have accumulated working outside
telco as customers. What really counts is that "a friend of a friend of
a friend sez..."
>And of course no one has seen the Phone Police kick down a door
>to confiscate that dreaded illegal short -- but they know a Friend of a
>Friend who has.
No kidding!
--
John Higdon | P.O. Box 7648 | +1 408 264 4115 | FAX:
jo...@ati.com | San Jose, CA 95150 | 10288 0 700 FOR-A-MOO | +1 408 264 4407
John Higdon
>This can save the phone company a non-trivial amount
>of power. I had 61 ma of short circuit current. That can easily run into
>2 to 3 watts of continuous power dissapation in the lines.
My goodness! I may be "wasting" 30 or 40 watts nationwide with busied
out lines! Dreadful!
Eric Bohlman
: This is the observed behavior of the phone system here. I have tested it
: by shorting the line with an LED in series with it. After a couple of
: minutes the LED will turn off. After that the LED will pulse momentarily
: every few minutes. When you remove the short the dial tone will return
: after the next polling pulse.
It wouldn't surprise me at all if your line would exhibit the *same*
behavior if you simply picked up a phone and left it off hook for a few
minutes. Have you tried it?
Mike Barnard
>Mistake here also. 600 ohm is the AC impedance of telephone
>transformer. The DC resistance is normally around 200-400 ohm.
No mistake. Impedence = resistance + reactance. Since your average
carbon-film resistor has no apprecable reactance at audio frequencies, you
must use a 600 ohm resistor if you expect to get 600 ohms of AC impedence.
Of course, the truth is that phone lines are quite forgiving, and quite a
wide range of values will work just fine.
John Lundgren
Jay Summet (j...@connected.com) wrote:
: I'm going to *ass*ume that you want to take a line "off-hook" when you
: say "busy the line out". There are two ways of doing this:
: 1. Take your phone, pick up the handset (Press TALK or whatever to get
: the dialtone) and walk away.
You are assuming wrong. We're talking about a bank of numerous modems,
some that may not be functional. The lines are in a hunting group, so
that a broken modem's line has to be made busy or else the callers will
get nothing but a constant ringing.
: 2. Place a 100-400 ohm resistor accross the line.
If you had read my earlier post, maybe you would have answered this
question: WHY? Please justify your statement with some concrete reason
that it is beneficial to use a resistor. Please....
I can give you several reasons to NOT use the resistor.
: Method 1 makes some noise, but is simple.
But not possible or economically feasible. There's no room for a few
phones in a rack of modems.
: Method 2 does not make noise, but takes some soldering. (Nobody, but
: NOBODY twists the wires!)
I wish you would tell that to our PacBell subcontractors. I think half
the time they run out of mouse rubbers and just twist 'em together and
add some electrical tape.
: If you want to, you can buy a device called a "external hold switch" from
: many places which is just a 100-400 ohm resister with a SPST switch and a
: LED attached to a RJ-11.
I really don't see any point in spending that much money.
Maybe you would volunteer to take one apart and send us a schematic. The
resistor is too low to limit the current to the LED, since the voltage is
48 Volts. It might be in parallel with the LED.
John Lundgren
Mark Miller (mem...@u.cc.utah.edu) wrote:
: My recommendation is to use either a large ( > 3K ) or small ( < 220 ohms)
: 1/2 watt resistor to generate the least local heat. A 1 K resistor gets
: quite hot very quickly.
Agreed about the least heat statement.
Greater than 3K resistance to take the line off hook has a couple
problems:
First off, not all lines go off hook at the same current. The original
requestor wanted several of these to use on a bank of modems. One line
may go off hook at 3K, and another line may not go off hook at that value.
*ALL* phone lines go off hook when shorted.
High values of resistance across the line pose a bigger hazard for fire
if there is a fault on the line. If a tree branch blows down and there
is a 220V line knocked down onto your phone lines, well, I hope your fire
insurance is paid up. And during a lightning storm, this high value
resistor may go up in smoke, too. Much easier and faster than a small
value or short.
: If you short the lines together, most phone systems will shut your line
: down and poll it every several minutes before they bring it back up again.
OH REALLY? Then what happens when you put a 3.3K resistor across the line??
The same thing!!
What happens when you put a short across the line?? The same thing!!
Don't bother trying to convince us that the CO switch knows the difference
between your 3K resistor, a telephone, or a short. It doesn't.
: - Mark.
John Lundgren
Ken Pizzini (k...@chinook.halcyon.com) wrote:
: In article <329fhg$l...@eis.calstate.edu>,
Yeah, I know that I can buy the modular RJ-45 connectors for either
stranded or solid wire. But I've never seen an RJ-11 connector for solid
wire, since just about everyone uses flat silver satin cable for RJ-11,
with the stranded 26 gauge wire. I've bought the connectors for stranded
at Rat Shack, but I've never seen the solid connectors available.
ANd, the average person wouldn't know or be able to see the difference
without a magnifying glass.
Thompson, Dave
In Telecom-Tech Digest 2.430, 11 Aug 1994 07:41:56 -0600,
mem...@u.cc.utah.edu (Mark Miller) answers a response from
David Lesher <wb8...@skybridge.scl.cwru.edu> :
>>Given there is many Kohms of drop, both in the drop, and the line relay
>>at the CO, how can the CO tell if you have 200, 100 or zero ohms?
>This is the observed behavior of the phone system here. I have tested it
>by shorting the line with an LED in series with it. After a couple of
>minutes the LED will turn off. After that the LED will pulse momentarily
>every few minutes. When you remove the short the dial tone will return
>after the next polling pulse.
And it doesn't do this with your "polite" 200-ohm or whatever resistor?
Every residential line I've had (MO, GA, several MA) if the instrument
is off-hook more than a few minutes changes from dialtone to either:
- an intermittent loud blatting noise, maybe about 1000Hz
- a recording like "there is trouble on your line, please hang up"
- some combination of the above with periods of silence (possibly
no battery, I never had a voltmeter on at the time)
(except one private step-by-step, which would leave dialtone, or ring
if neither answered or abandoned, forever until a *person* intervened)
Presumably this is to (pick one or more):
- prevent you from tying up DTMF recognizers, digit registers, etc.,
depending on CO type
- prevent you from unintentionally blocking incoming (and possibly
revenue-generating) calls (this thread is about the case where you
*do* want to, but that's not "normal")
- prevent your worried relatives/friends from wasting operator time
with verification requests
The only disadvantage I've heard of a simple wire is that, especially
if you don't tag it or put up a sign, a repairperson working on
something else may decide it looks like a mistake and remove it.
A resistor, or LED, is more obviously "doing something".
>I measured the *effective* CO line resistance at 852 ohms, not
>"many Kohms" on a dead short. This includes the effective resistance
>of the current limiting circuitry in the CO. It is trivial for the CO to
>shut down a line temporarily if the current rises above a specified
>maximum, although this may only happen if you are near the CO. I live 0.7
>miles down the road. This can save the phone company a non-trivial amount
>of power. I had 61 ma of short circuit current. That can easily run into
>2 to 3 watts of continuous power dissapation in the lines.
Although some power is wasted, as long as they're not on backup power
(e.g. due to a blackout) I doubt it's a problem.
I recall reading years back Teletype (& TWX?) lines were 60ma nominal
(later 20ma); maybe someone (presumably Bell Labs) had determined this
was the maximum safe over some suitable sample of outside plant?
- Dave Thompson, da...@fpg.logica.com
Logica North America, +1 617-890-7730
Brett Frankenberger
>In article <32d9r4$6...@u.cc.utah.edu> mem...@u.cc.utah.edu (Mark Miller) writes:
>
>>This can save the phone company a non-trivial amount
>>of power. I had 61 ma of short circuit current. That can easily run into
>>2 to 3 watts of continuous power dissapation in the lines.
>
>My goodness! I may be "wasting" 30 or 40 watts nationwide with busied
>out lines! Dreadful!
So how many ohms to you reccommend? Under your example, 48 volts and 61ma
would be about 800 ohms ... since in a constant voltage situation,
power is inversly proportional to resistance, even if you put in a 800
ohm resistor, you only cut power consumption in half ... since many of
the posts I saw talked about a 100 to 200 omh resistor, we are only
looking at a 20% or less reduction in power ... seems relatively
trivial to me ...
--
- Brett (bre...@netcom.com)
------------------------------------------------------------------------------
... Coming soon to a | Brett Frankenberger
.sig near you ... a Humorous Quote ... | bre...@netcom.com
Tom Ace
In article <brettfCu...@netcom.com> bre...@netcom.com
(Brett Frankenberger) writes:
>jo...@zygot.ati.com (John Higdon) writes:
>
>>My goodness! I may be "wasting" 30 or 40 watts nationwide with busied
>>out lines! Dreadful!
>
>So how many ohms to you reccommend?
In case John is tired of saying it, he recommends zero ohms.
I made a few measurements to find out for myself what was going on.
If I short my residence POTS line, it draws 40-45 ma for about 80
seconds, with brief interruptions as it switches from dial tone to
announcement to receiver off-hook tone. Current then drops to about
25 ma, thus dissipating 1.25 watts in my local loop of about 2000 ohms.
That works out to about a dime's worth of energy per month. I'm not
surprised that the telco doesn't consider it a big deal.
Tom Ace
t...@netcom.com
Ken Pizzini
John Lundgren <jlun...@news.kn.PacBell.COM> wrote:
>: There are two varieties of connectors: one designed for stranded wire
>: and one designed for solid wire.
>
>stranded or solid wire. But I've never seen an RJ-11 connector for solid
>wire, since just about everyone uses flat silver satin cable for RJ-11,
>with the stranded 26 gauge wire. I've bought the connectors for stranded
>at Rat Shack, but I've never seen the solid connectors available.
I haven't seen them at any "general consumer" stores either,
but as you say, most "general consumers" will be buying them
to connect to silver satin cable. I've seen them available
from Brand Rex, and from Time Motion Tools. For the latter
I see that 4-position RJ-11 connectors run $16.95/100 for
round stranded cable, $23.95/100 for flat stranded cable, and
$24.95/100 for round solid cable.
>ANd, the average person wouldn't know or be able to see the difference
>without a magnifying glass.
True enough. I don't find a magnifying glass necessary, but
most people wouldn't even know that the connectors are different.
--Ken Pizzini
Mark Miller
I just tried it with an LED and 1K resistor in series with an off hook
phone. You are correct. The CO drops all current after about three
minutes of off hook condition, and then polls using a brief current pulse
about once every thirty seconds.
- Mark.
Floyd Davidson
The switch (actually the line card in the switch) probably current
limits the loop at 60ma. If you were a few miles from the switch
the current would be less, but it would always be at least 20ma,
because that is the definition of an offhook condition (in the US,
but it may be more or less in other countries).
The fact that 20ma or more of loop current is flowing is defined as
an offhook condition, and when the switch detects it a sequence of
events takes place that will, with your particular switch, end up
doing as you have described. Other switches may do it slightly
different. But in any case it is all triggered by the flow of
a minimum of 20ma of current. The fact that your loop is 800 ohms
or 2400 ohms isn't important and has no significance at all. If
you use a dead short or a resister of some arbitrary size, all
that matters is a minimum of 20 ma of current.
As to the total amount of power... it is _less_ than trivial. As
you have pointed out, in your case the telco shuts it off and only
tests your line with it every few minutes. But even if the loop
was active all the time it only amounts to 3 watts of power. In
333 hours that is 1Kw hour. What does that amount to per day? It
would cost that much in postage just to send you a letter once a
month explaining it (never mind the hundreds of thousands of
dollars that each of these articles posted to Usenet cost! :-).
Hmmm... I never thought of it before, but no wonder we always
short the darned things to cause an offhook: It would 12.3 years
(rough calculation) of constant use to save enough on the electric
bill to pay for one resister! If my boss found out I was buying
things with more than an 10 year expected payback, I'd be in big
trouble.
Mark Miller
Floyd Davidson <fl...@hayes.ims.alaska.edu> wrote:
>As to the total amount of power... it is _less_ than trivial. As
>you have pointed out, in your case the telco shuts it off and only
>tests your line with it every few minutes. But even if the loop
>was active all the time it only amounts to 3 watts of power. In
>333 hours that is 1Kw hour. What does that amount to per day? It
>would cost that much in postage just to send you a letter once a
>month explaining it (never mind the hundreds of thousands of
>dollars that each of these articles posted to Usenet cost! :-).
I keep hearing this astronomical estimate about the cost of a news article.
This article is about 1 kilobyte. I understand that there is currently
about 45 MB of news each day. At $100,000 per article that is an estimated
cost of 1.64 TRILLION DOLLARS per year. I think that is a little
unrealistic.
My estimate is closer to 8 dollars per article, with a total system wide
newsfeed cost of 131 million dollars per year.
Marginal Cost Assumptions:
^^^^^^^^
Hard drive space: $ 2.00 / megabyte
Processor capacity: $ 50.00 per MIPS.
Comm hardware: $ 75.00 / megabyte per hour transmission capacity
( 14400 baud modem + interface )
$ 8.00 / megabyte per hour transmission capacity
( T1 CSU/DSU & router )
Comm Charges: $ 0.02 / megabyte data transmitted.
( 14400 baud connection, 1000 bytes per second, $50/mo phone line).
$ 0.003 / megabyte data transmitted
( T1 line, 1.544 mbps, $2000/mo connection )
Processor Overhead: 100 million instructions executed / megabyte.
USENET Article length: 1 kilobyte.
Average Article lifetime: 1 month.
Total Internet Nodes: 3 million.
Effective percentage with full news feeds: 3% ( 100,000 sites )
Marginal transmission hops per system: 1.0
Derived quantities (based on 3 yr straight line amortization):
--------------------------------------------------------------
Hard drive space: $ 0.06 per megabyte per month
Cost of article storage: $ 0.06 per megabyte of articles per system
Processor Time: $ 5e-7 per million instructions.
Cost of article processing: $ 5e-5 per megabyte of articles per system.
Comm Hardware: $ 0.003 per megabyte data transmitted (modem)
$ 3e-4 per megabyte of data transmistted (T1)
Comm Charges: $ 0.02 per megabyte ( modem, carried down )
$ 0.003 per megabyte ( modem, carried down )
Total cost per megabyte of articles, per system (worst case): $ 0.08
Total cost per megabyte of articles, all systems: $ 8000.00
Total cost per article, all systems: $ 8.00
^^^^^^^
Total newsfeed cost, all systems (45 MB/day): $ 131 million / year
This sounds a little more realistic to me. I welcome your comments.
- Mark.
Floyd Davidson
>In article <CuGG7...@raven.alaska.edu>,
>Floyd Davidson <fl...@hayes.ims.alaska.edu> wrote:
>
>>As to the total amount of power... it is _less_ than trivial. As
>>you have pointed out, in your case the telco shuts it off and only
>>tests your line with it every few minutes. But even if the loop
>>was active all the time it only amounts to 3 watts of power. In
>>333 hours that is 1Kw hour. What does that amount to per day? It
>>would cost that much in postage just to send you a letter once a
>>month explaining it (never mind the hundreds of thousands of
>>dollars that each of these articles posted to Usenet cost! :-).
>
>I keep hearing this astronomical estimate about the cost of a news article.
>
>This article is about 1 kilobyte. I understand that there is currently
>about 45 MB of news each day. At $100,000 per article that is an estimated
>cost of 1.64 TRILLION DOLLARS per year. I think that is a little
>unrealistic.
Only about as unrealistic as your concept of the cost of loop power
on a busy telphone line. :-) <<=== smileys mean don't take it
all too serious. (Note the other one up above... :-)
...
>Total cost per article, all systems: $ 8.00
> ^^^^^^^
>Total newsfeed cost, all systems (45 MB/day): $ 131 million / year
>
>This sounds a little more realistic to me. I welcome your comments.
IMHO that is close. But you have to know about two things to
really get a grasp on it. 1) nobody who says "IMHO" is being
humble, and 2) back in the good old days, years before aol.com,
and the hoards of people who messed up the net _after_ I got here
(it was _developing_ up to that time, and has been "going down
hill" since!); there was this funny little statement that came
with rn or Postnews or whatever it was that said so, which asked
if you really wanted to post your article considering the hundreds
of thousands of dollars expense it was going to cost the net.
It was a joke, but the moral of the story was worth knowing:
this crap is a waste of bandwidth.
Gordon Torrie
|
| This article is about 1 kilobyte. I understand that there is currently
| about 45 MB of news each day. At $100,000 per article that is an estimated
| cost of 1.64 TRILLION DOLLARS per year. I think that is a little
| unrealistic.
|
| My estimate is closer to 8 dollars per article, with a total system wide
| newsfeed cost of 131 million dollars per year.
|
| Marginal Cost Assumptions:
| ^^^^^^^^
| Total cost per article, all systems: $ 8.00
| ^^^^^^^
| Total newsfeed cost, all systems (45 MB/day): $ 131 million / year
|
| This sounds a little more realistic to me. I welcome your comments.
A very similar sort of analysis is performed every month by Brian
Reid <re...@decwrl.dec.com> and posted to the newsgroups
news.groups, news.lists, and news.admin.misc with the subjects
USENET READERSHIP REPORT FOR JUL 94
USENET READERSHIP SUMMARY REPORT FOR JUL 94
(or whatever the current month and year are).
Brian Reid has a somewhat different understanding of the total
number of USENET sites and the average amount of news per day
(190,000 sites and 189.135 Mbytes/day during July 1994).
In addition, Brian Reid also posts an article describing how many
sites store news for how long in the newsgroups news.groups,
news.lists, news.admin.misc, and news.lists.ps-maps with the
subject:
USENET FLOW ANALYSIS for JUN 94: Who stores how much news
(or whatever the current month and year are).
You might want to review these articles before continuing your
analysis. In each of them, Brian Reid describes how he obtained
the results and the assumptions he made and why.
--
gor...@torrie.org Gord Torrie
Ken Pizzini
Floyd Davidson <fl...@hayes.ims.alaska.edu> wrote:
>IMHO that is close. But you have to know about two things to
>really get a grasp on it. 1) nobody who says "IMHO" is being
>humble,
I tend to read that as "in my *honest* opinion", although
I suspect that many who say IMHO aren't being honest either :-).
>with rn or Postnews or whatever it was that said so, which asked
>if you really wanted to post your article considering the hundreds
>of thousands of dollars expense it was going to cost the net.
As I recall it it was "hundreds if not thousands of dollars".
Still a bit of hyperbole, but not as bad.
Sorry for the off-charter response...
--Ken Pizzini
John Egan
: non-functioning modems be "busy" (that is, "off hook") until the
: modems are fixed. This will have the effect of preventing
: dial-in-ers from getting the broken modems.
Try a 100K resistor across the ring and tip .....
John Lundgren
John Egan (je...@crl.com) wrote:
: : What I'd like is to be make the incoming telephone lines hooked up to
Here we go again. Is this guy serious?
A half milliamp isn't going to take any phone line off hook!!
OK, OK. I'll concede. Your guys were right. We should use a resistor.
But it has to be 100 milliohms.
(That's roughly about the resistance of a foot-long piece of 26 ga. silver
satin.)
<snicker>
Bohdan Tashchuk
>>This can save the phone company a non-trivial amount
>>of power. I had 61 ma of short circuit current. That can easily run into
>>2 to 3 watts of continuous power dissapation in the lines.
>My goodness! I may be "wasting" 30 or 40 watts nationwide with busied
>out lines! Dreadful!
Yeah. The global-warming Eco-nuts are probably very upset at you.
On the other hand, you may be helping to save us from another ice age.
--
Bohdan The Failed Clinton Presidency - America Held Hostage - Day 572
John Lundgren
V. George Blackwell (vgbla...@miavx1.acs.muohio.edu) wrote:
: In article <1994Aug12....@zygot.ati.com>, jo...@zygot.ati.com (John Higdon) writes:
: > In article <wb8fozCu...@netcom.com> wb8...@skybridge.scl.cwru.edu (David Lesher) writes:
: >
: >>This seems to have as many lives here as the "Postcards for
: >>Craig Shergold" one in alt.folklore.urban.
: I have been reading all over the place about making a busy signal on the
: telephone line.
: I hope my question is simple, but why do it? Can someone present a idea of
: why anyone would want to do this. And by the way shorting out the line will
: positively do it. But please give me a for-instance.
: George
You must have missed the one post answering the similar Q. You have three
modems on 555-5555, 555-5556, and 555-5557, on a rotary or hunt group,
i.e., the phone system chooses the next available line.
The middle modem goes dead. Someone is already using the first modem.
The next modem would have normally answered, but since it's dead, it just
rings and rings. By busying out this line, the third modem will be
rotaried to and get the ring, and the modem will answer.
This is very important since it can cause acute frustration to the
callers if it isn't done.
--
Jon Sreekanth
This is the way it works in the real world. As I have said before, I
have an open mind. If someone can produce a single verifiable case of an
intentionally dead-shorted line resulting in any harm whatsoever, it
will be taken under due consideration. Until then, folks, save your
money; save your time; save your aggrevation. Short it out!
I know this thread has popped up many times, but I also recollect
ATT Princess phones being supposedly a fire hazard under some
circumstances. Is there any interaction between the two subjects ?
/ Jon Sreekanth
Assabet Valley Microsystems, Inc. | Fax and PC products
5 Walden St #3, Cambridge, MA 02140 | (617) 876-8019
jon_...@world.std.com |
V. George Blackwell
>
>>This seems to have as many lives here as the "Postcards for
>>Craig Shergold" one in alt.folklore.urban.
>>
Rich Greenberg
indicates that it is moderated, but uunet rejects the moderator
email address as invalid.
Is it pseudo-moderated as is alt.hackers?
In article <JON_SREE.94...@world.std.com> jon_...@world.std.com (Jon Sreekanth) writes:
{shorting a line to busy it out]
>I know this thread has popped up many times, but I also recollect
>ATT Princess phones being supposedly a fire hazard under some
>circumstances. Is there any interaction between the two subjects ?
No.
The Princess phones (and older trimlines also) used an external transformer
to supply low voltage a.c. (6 volts I think) for the lights on the dials.
If this transformer or its wireing (often the yellow-black pair on quad
wire) is shorted, this can cause a fire.
--
Rich Greenberg Work: TBA. Know anybody needing a VM guru?
N6LRT TinselTown, USA Play: ric...@netcom.com 310-649-0238
Pacific time. I speak for myself and my dogs only. Canines: Chinook & Husky
Chris Schmidt
>vgbla...@miavx1.acs.muohio.edu (V. George Blackwell) wrote:
>> I hope my question is simple, but why do it [busy out a phone line]?
>The classic scenario is you have a modem bank on a set of lines set up to
>hunt (i.e. you dial the first number and it rings the first free modem).
>If a modem in the middle of the hunt group dies, you need some way to tell
>the phone switch to skip over that number when hunting, otherwise the rest
>of the bank becomes unavailable. The simpliest way to do this is to
>busy-out the phone line.
Ya, put a cheap phone on the line, disconnect the Speaker, and leave
it off the hook. Or like I think the other guys were trying to say,
put a 200-800 ohm resistor across the wires. About a 1/2 watt or bigger
I am assuming to reduce the risk of fire. =-)
Chris
John Lundgren
Chris Schmidt (csch...@diralect.me.pvamu.edu) wrote:
: r...@nyu.edu (Roy Smith) writes:
We are all ears out here waiting for an answer to the question; 'why do
you need to put a resistor across the line?'
We offer the following. There is no need for it, there is no reason for
it, and putting a resistor there is a waste of money, and creates a
possible fire hazard. All the phone personnel use a piece of plain wire
to busy out the line. Why shouldn't you?
Please give us some reason that it's necessary, not just an answer that
'the gods willed it'.
BTW, using a phone off the hook is totally out of the question. In a
bank of a couple hundred modems, there is no room for 5 or 10 phones, and
there is no room in the budget for a couple hundred dollars.
Bill Mayhew
offers sufficient disspation for the power in the loop current.
Using a resitor is a waste of time and is worse becuase if you pick
a reistor which is too small in wattage, the resistor could burn
up.
A shorting clip on a 66 block or a hunk of wire criped in a modular
jack is not going to burn up.
This discussion thread must be trying to win a race with sending
postcards to the boy in England or Making Money Fast for being the
most over-discussed topic on the net.
--
Bill Mayhew NEOUCOM Computer Services Department
Rootstown, OH 44272-0095 USA phone: 216-325-2511
w...@uhura.neoucom.edu amateur radio 146.58: N8WED
Clifton T. Sharp
>nb: alt.2600 removed from newsgroups line. This site's active file
>indicates that it is moderated, but uunet rejects the moderator
>email address as invalid.
>Is it pseudo-moderated as is alt.hackers?
No, some jokers keep changing it with forged control messages.
>In article <JON_SREE.94...@world.std.com> jon_...@world.std.com (Jon Sreekanth) writes:
>>I know this thread has popped up many times, but I also recollect
>>ATT Princess phones being supposedly a fire hazard under some
>>circumstances. Is there any interaction between the two subjects ?
>
>No.
Wrong-o.
>The Princess phones (and older trimlines also) used an external transformer
>to supply low voltage a.c. (6 volts I think) for the lights on the dials.
In some cases this transformer had some sort of insulation problem and
could overheat and smoke (and presumably catch fire). A mailing with our
phone bill one month asked us to look at our transformer to see if it had
a particular manufacturer name and part number on it, and bring it in for
exchange (or call Repair Service) if it did.
--
Optimists say, "The glass is half full."
Cliff Sharp Pessimists say, "It's half empty."
WA9PDM We realists say, "Before I decide,
cli...@indep1.chi.il.us tell me what's in the glass."
C.A. Peskin
call your telephone company and have them "BUSY" the line out. The line
is STILL operable, you may dial out. No dial in will be allowed. Why
not do THIS?!
--
+------------------------------------------------------------------+
| Rochester Institute of Technology Chris A. Peskin |
| Electrical Engineering |
+------------------------------------------------------------------+
John Lundgren
C.A. Peskin (cap...@ultb.isc.rit.edu) wrote:
: If you jave a hunt group and have, say line one, malfunctioning, you may
: call your telephone company and have them "BUSY" the line out. The line
: is STILL operable, you may dial out. No dial in will be allowed. Why
: not do THIS?!
First off, the phone company takes their own sweet time. They will
commit to a window of four hours to clear a trouble ticket, and I've seen
them take longer, especially if they have to use manpower. And we have
the "priority business" service. Ahem.
Second, the phone co wants some money whenever we have them make a change
on our Centrex lines. SO using a jumper is a lot cheaper and faster.
John Higdon
>If you jave a hunt group and have, say line one, malfunctioning, you may
>call your telephone company and have them "BUSY" the line out. The line
>is STILL operable, you may dial out. No dial in will be allowed. Why
>not do THIS?!
It takes about one second to short out a phone line. It takes about
five or ten minutes just to wade through the voicemail jail at telco,
then you have to speak to a person who does not say, "we can't do that"
on a kneejerk basis, and THEN when the need for the busy goes away you
must go through that all over again to get someone to clear the
busy--maybe hours later.
I hope that explains it.
--
John Higdon | P.O. Box 7648 | +1 408 264 4115 | FAX:
jo...@ati.com | San Jose, CA 95150 | 10288 0 700 FOR-A-MOO | +1 408 264 4407
Floyd Davidson
>In article <1994Aug27.0...@ultb.isc.rit.edu> cap...@ultb.isc.rit.edu (C.A. Peskin) writes:
>
>>If you jave a hunt group and have, say line one, malfunctioning, you may
>>call your telephone company and have them "BUSY" the line out. The line
>>is STILL operable, you may dial out. No dial in will be allowed. Why
>>not do THIS?!
>
>It takes about one second to short out a phone line. It takes about
>five or ten minutes just to wade through the voicemail jail at telco,
>then you have to speak to a person who does not say, "we can't do that"
>on a kneejerk basis, and THEN when the need for the busy goes away you
>must go through that all over again to get someone to clear the
>busy--maybe hours later.
>
>I hope that explains it.
That half explains it, here is the other half:
Ask for that service once and discussion during the next break is
going to be about how to make sure you NEVER ask again. The
response time is not going to be accidental.
Bruce Kriskovich
available in software? Ours does. Why not do that and eliminate CO's
wires, resistors, et al?
John Lundgren (jlun...@news.kn.PacBell.COM) wrote:
John Lundgren
Bruce Kriskovich (b...@sun.lclark.edu) wrote:
: Am I not correct in assuming that most PBX's have a 'Busy Out' feature
: available in software? Ours does. Why not do that and eliminate CO's
: wires, resistors, et al?
As I mentioned below, we have Centrex, and our modems don't go thru a
PBX, but just go straight to the CO. We have a PBX, but all the lines
going to phones are digital, and a modem can't be used on that kind of
line. And since Centrex features are not needed on a modem line, and
just costs extra, most of our modem lines are not Centrex, but just
straight measured business lines.
I can't see why anyone would want to connect a modem to the PBX. The
modem doesn't need any features except being on a hunt group, in other
words, contention. They mostly receive calls, and don't dial out. And
there are often so many modems that the extra cost of PBX lines and SLICs
would make it too expensive.
: John Lundgren (jlun...@news.kn.PacBell.COM) wrote:
: : C.A. Peskin (cap...@ultb.isc.rit.edu) wrote:
: : : If you jave a hunt group and have, say line one, malfunctioning, you may
: : : call your telephone company and have them "BUSY" the line out. The line
: : : is STILL operable, you may dial out. No dial in will be allowed. Why
: : : not do THIS?!
: : First off, the phone company takes their own sweet time. They will
: : commit to a window of four hours to clear a trouble ticket, and I've seen
: : them take longer, especially if they have to use manpower. And we have
: : the "priority business" service. Ahem.
: : Second, the phone co wants some money whenever we have them make a change
: : on our Centrex lines. SO using a jumper is a lot cheaper and faster.
--
Arik Baratz
Takes less time than to short the wires, and your phone is free to dial out.
Arik
P.S. also good to prevent "waiting call" service when your phone co
doesn't allow *70.
Arik
John Lundgren
Arik Baratz (s320...@techst02.technion.ac.il) wrote:
: Anyone thought about doing call-forward to yourselves? Works for me.
When an installation has several dozen to several hundred modems and
phone lines, there just isn't any advantage, and numerous disadvantages,
to having any features on the lines. The BIG disadvantage is money.
Features cost extra, and with that many lines, are just too expensive.
We had a fax machine that was getting dozens of calls every day, without
ever receiving a fax. After many complaints, we had to generate the
paperwork to send to the phone company to do a trace to see where
they were coming from. Then all of a sudden the calls stopped.
Often we have found that problems similar to this are caused when someone
has made a mistake when they call forwarded their phone to another
incorrect number.
I guess it's the original case where a problem with users manifests
itself in symptoms that seem to be with the phone system.
Lee Davidson
> Anyone thought about doing call-forward to yourselves? Works for me.
>Takes less time than to short the wires, and your phone is free to dial out.
An LSSGR Call Forwarding compliant switch does not allow activation of
call forwarding from a line to the same line (at least it didn't 8
years ago when I had to help code it up for the AXE). There are also
other scenarios to avoid, like forwarding loops (both within a switch
and, more troublesome, in the network). This "network loop" case,
along with the additional work to generate AMA records for the
forwarded leg, are, I believe, the two main reasons that many older
systems restrict forwarding to within the switch. More recently,
support for additional number transfer capability has had to be added
to all switches to properly handle ANI and such in the network.
The LSSGR forwarding services offer an option called "confirmation
call" which may be used to reduce the number of errant forwardings. At
least, technically, the capability is there in LSSGR-compliant
systems. Does anyone know if it is available? I'd hate to think the
time it took to design all those options was wasted.
Lee Davidson (le...@eru.ericsson.se)
Gary Breuckman
John Lundgren <jlun...@news.kn.PacBell.COM> wrote:
>I can't see why anyone would want to connect a modem to the PBX. The
>modem doesn't need any features except being on a hunt group, in other
>words, contention. They mostly receive calls, and don't dial out. And
>there are often so many modems that the extra cost of PBX lines and SLICs
>would make it too expensive.
I can see one reason, if you didn't have a large number of modems, and
wanted to use DID lines, you might consider doing that. But for lots
of modems, in use much of the time, it makes sense to put them on their
own telco lines.
Brett Frankenberger
>I can't see why anyone would want to connect a modem to the PBX. The
>modem doesn't need any features except being on a hunt group, in other
>words, contention. They mostly receive calls, and don't dial out. And
>there are often so many modems that the extra cost of PBX lines and SLICs
>would make it too expensive.
Top Reasons to Connect a Modem Dial-In Pool To a PBX
(1) You have a private network and want to be able to dial the modems
that way to same charges. (In a falt-rate service area, you could
still do it by having the call come to the local PBX on the private
network and then be forwarded out to the local CO - it wouldn't cost
anything since the LD charges would be avoided ... but in a measured
service area, you'd pay for the outgoing call from the PBX.)
(2) You have a lot of incoming lines into the switch that are unused at
night and most of your modem usage is at night, so you can install the
modems behind the PBX and not have to buy any additional lines.
(3) You already have 1-800 DNIS service to your switch and want to use
an 800# on your modems. (See #1 ... if you have flat rate service and
plenty of pree outbound lines, you can just send the 800# call out to
the CO).
(4) You also use the modems our outbound modem-sharing and want the
call accounting and least-cost routing provided by your PBX.
(5) You can use the ACD features of some PBXs to automatically stop
sending calls to broken modems.
--
- Brett (bre...@netcom.com)
------------------------------------------------------------------------------
... Coming soon to a | Brett Frankenberger
.sig near you ... a Humorous Quote ... | bre...@netcom.com
David Cornutt
>jlun...@news.kn.PacBell.COM (John Lundgren) writes:
>>I can't see why anyone would want to connect a modem to the PBX...
>Top Reasons to Connect a Modem Dial-In Pool To a PBX
[very good reasons 1-5 deleted]
(6) You have a small business with only 2-3 lines. You can't afford
to dedicate a line to a modem, and want to avoid any goofy line-
switching arrangements that would require the sales folks to learn
any more about telecomm than they really want/need to know.
Dave
--
David Cornutt, Huntsville, AL (205) 461-0087 Dave.C...@lambada.oit.unc.edu
The preceding material does not represent the opinions of NASA or my empolyer.
Ignorance is not a sin. Pride in ignorance is.
John Lundgren
Brett Frankenberger (bre...@netcom.com) wrote:
: jlun...@news.kn.PacBell.COM (John Lundgren) writes:
: >I can't see why anyone would want to connect a modem to the PBX. The
: >modem doesn't need any features except being on a hunt group, in other
: >words, contention. They mostly receive calls, and don't dial out. And
: >there are often so many modems that the extra cost of PBX lines and SLICs
: >would make it too expensive.
Since our college district deals with callers that are, for the most
part, in a single area code, and a single metro area, my viewpoint is
slanted.
: Top Reasons to Connect a Modem Dial-In Pool To a PBX
: (1) You have a private network and want to be able to dial the modems
: that way to same charges. (In a falt-rate service area, you could
: still do it by having the call come to the local PBX on the private
: network and then be forwarded out to the local CO - it wouldn't cost
: anything since the LD charges would be avoided ... but in a measured
: service area, you'd pay for the outgoing call from the PBX.)
Since we use Centrex, none of this can be done on our network.
: (2) You have a lot of incoming lines into the switch that are unused at
: night and most of your modem usage is at night, so you can install the
: modems behind the PBX and not have to buy any additional lines.
I don't follow this one. The number that is dialed is the main PBX number,
plus an extension that is for the modem group. This can't be done on our
network, because we have Centrex.
Also our modem usage isn't necessarily heaviest in the evening. And if
the modem usage is not predictable, then the line usage may exceed the
peak in the daytime, and then the users get busy signals.
: (3) You already have 1-800 DNIS service to your switch and want to use
: an 800# on your modems. (See #1 ... if you have flat rate service and
: plenty of pree outbound lines, you can just send the 800# call out to
: the CO).
See my first paragraph.
: (4) You also use the modems our outbound modem-sharing and want the
: call accounting and least-cost routing provided by your PBX.
Most of the calls are incoming in my case. Modems are usually answer
only, in large quantities.
: (5) You can use the ACD features of some PBXs to automatically stop
: sending calls to broken modems.
: --
: - Brett (bre...@netcom.com)
--
John Lundgren
David Cornutt (cor...@lambda.msfc.nasa.gov) wrote:
: bre...@netcom.com (Brett Frankenberger) writes:
: >jlun...@news.kn.PacBell.COM (John Lundgren) writes:
: >>I can't see why anyone would want to connect a modem to the PBX...
: >Top Reasons to Connect a Modem Dial-In Pool To a PBX
: [very good reasons 1-5 deleted]
: (6) You have a small business with only 2-3 lines. You can't afford
: to dedicate a line to a modem, and want to avoid any goofy line-
: switching arrangements that would require the sales folks to learn
: any more about telecomm than they really want/need to know.
: Dave
With only 2 or 3 lines, I'm assuming that the business only has a single
modem. The original thread was dealing with modem pools, i.e., multiple
modems.
Larry Meadows
>: (6) You have a small business with only 2-3 lines. You can't afford
>: to dedicate a line to a modem, and want to avoid any goofy line-
>: switching arrangements that would require the sales folks to learn
>: any more about telecomm than they really want/need to know.
>: Dave
>With only 2 or 3 lines, I'm assuming that the business only has a single
>modem. The original thread was dealing with modem pools, i.e., multiple
>modems.
We have 8 lines, 6 modems, and one fax machine. All modems are connected
to the PBX, as is the fax machine. During the day, the PBX directs 3 of
the modem lines to normal dialin phone lines. During the night, those 3
lines connect directly to the modems. So at night and on weekends, we have
6 active modem lines, and during the day we have three.
All of these lines can be used as outgoing lines during day or nite. The fax
line always goes to the fax but can be used as outgoing. The PBX can tell
if a line is busy and doesn't select it as an outgoing line.
It isn't perfect but it really beats what we had before, involving line
connections thru modems and manual timers. And we've more-or-less solved
both the work-at-home problem and the customer-gets-busy-signal problem.
Our scheme would work with 2 or 3 lines as well, but the cost of the phone
system is probably too high. 4 starts to break even when you consider fax.
7 lines costs about $350/month, I haven't figured out if I'm supposed to
pay the $60/month for PBX lines or the $40/month for direct-connect lines,
and GTE doesn't know or doesn't care. While this is a relatively small
cost, it is a recurring cost, and the cost savings multiplexing the lines
outweigh the very occasional conflicts between modem, voice, and fax users.
BTW, the phone system we use allows regular analog connections from the
extensions, so you can hook up a modem at your desk and use regular phones,
and it cost under $3000 for 32 stations. We installed it ourselves and I
think it was one of the best selections we've made (after spending 6 months
being wined and dined by every phone system sales operation in the Pacific
Northwest).
lfm
John Lundgren
: jlun...@news.kn.PacBell.COM (John Lundgren) writes:
: >: (6) You have a small business with only 2-3 lines. You can't afford
: >: to dedicate a line to a modem, and want to avoid any goofy line-
: >: switching arrangements that would require the sales folks to learn
: >: any more about telecomm than they really want/need to know.
: >: Dave
: >With only 2 or 3 lines, I'm assuming that the business only has a single
: >modem. The original thread was dealing with modem pools, i.e., multiple
: >modems.
You were deceptive. You led us to believe that you only had 3 lines.
: We have 8 lines, 6 modems, and one fax machine. All modems are connected
: to the PBX, as is the fax machine. During the day, the PBX directs 3 of
: the modem lines to normal dialin phone lines. During the night, those 3
: lines connect directly to the modems. So at night and on weekends, we have
: 6 active modem lines, and during the day we have three.
: All of these lines can be used as outgoing lines during day or nite. The fax
: line always goes to the fax but can be used as outgoing. The PBX can tell
: if a line is busy and doesn't select it as an outgoing line.
: It isn't perfect but it really beats what we had before, involving line
: connections thru modems and manual timers. And we've more-or-less solved
: both the work-at-home problem and the customer-gets-busy-signal problem.
: Our scheme would work with 2 or 3 lines as well, but the cost of the phone
: system is probably too high. 4 starts to break even when you consider fax.
: 7 lines costs about $350/month, I haven't figured out if I'm supposed to
: pay the $60/month for PBX lines or the $40/month for direct-connect lines,
: and GTE doesn't know or doesn't care. While this is a relatively small
: cost, it is a recurring cost, and the cost savings multiplexing the lines
: outweigh the very occasional conflicts between modem, voice, and fax users.
: BTW, the phone system we use allows regular analog connections from the
: extensions, so you can hook up a modem at your desk and use regular phones,
: and it cost under $3000 for 32 stations. We installed it ourselves and I
: think it was one of the best selections we've made (after spending 6 months
: being wined and dined by every phone system sales operation in the Pacific
: Northwest).
: lfm
Sounds pretty sophisticated. But when the lines are numerous, such as
ours and other sites, the cost could be astronomical.
[Q] How many pairs of wires does each phone require? I'm assuming that
it takes more than one if the phones require power and supervision, etc.
But if they are dumb phones, I guess they wouldn't require either.
Hmmm. There must be some way the PBX gets info from the phone. Only
using DTMF, or ???
Does the PBX prevent unauthorized long distance or toll calls?
Larry Meadows
>Larry Meadows (l...@pgroup.com) wrote:
>: jlun...@news.kn.PacBell.COM (John Lundgren) writes:
>: >: (6) You have a small business with only 2-3 lines. You can't afford
>: >: to dedicate a line to a modem, and want to avoid any goofy line-
>: >: switching arrangements that would require the sales folks to learn
>: >: any more about telecomm than they really want/need to know.
>: >: Dave
>: >With only 2 or 3 lines, I'm assuming that the business only has a single
>: >modem. The original thread was dealing with modem pools, i.e., multiple
>: >modems.
>You were deceptive. You led us to believe that you only had 3 lines.
Sorry, John, I messed up the editing. I managed to lose
the posting from the poster with only 3 lines. I was simply responding to
'why would one hook a modem to a pbx'.
> [ comments about prohibitive costs for big systems ]
Yes, I agree. My solution is somewhat maintenance intensive and does not
scale over, say, 10 lines and 40 extensions. But it works well for the
small phone system. "Use the right tool for the job" or some such.
>[Q] How many pairs of wires does each phone require? I'm assuming that
>it takes more than one if the phones require power and supervision, etc.
>But if they are dumb phones, I guess they wouldn't require either.
>Hmmm. There must be some way the PBX gets info from the phone. Only
>using DTMF, or ???
On the cheapy phones, DTMF.
Our PBX is one of the newer panasonic jobbies, 32 lines max. Funny thing
was, the system we used before cost almost as much, required special phones
and 4-wire lines, didn't allow modems from the phones, and didn't have
the features that we use now. Of course, the old system was purchased in
1989 and the new one in 1993.
We use 2 kinds of phones. The dumb ones require 2 wires, the smart ones
require 4. They have lots of cool buttons that emulate what can be done
with DTMF on the dumb phones.
There is also a PBX-desk-thingy that requires 6 but we don't
use it. We did, however, wire every jack w/ 4 wires so that we can put
the fancy phones anywhere.
>Does the PBX prevent unauthorized long distance or toll calls?
I think that that can be programmed per extension. Fortunately I don't
have to worry about it (small company, few rules -- I did say that it
doesn't scale).
lfm
Mike Garvey
scribed this stuff:
>[...]
>
>As I mentioned below, we have Centrex, and our modems don't go thru a
>PBX, but just go straight to the CO. We have a PBX, but all the lines
>going to phones are digital, and a modem can't be used on that kind of
>line. And since Centrex features are not needed on a modem line, and
>just costs extra, most of our modem lines are not Centrex, but just
>straight measured business lines.
>
>I can't see why anyone would want to connect a modem to the PBX. The
>modem doesn't need any features except being on a hunt group, in other
>words, contention. They mostly receive calls, and don't dial out. And
>there are often so many modems that the extra cost of PBX lines and SLICs
>would make it too expensive.
>
>[...]
Also, with tariffs being what they are, if you have need for a LOT of
modems, it's often cheaper to multiplex your modem lines off of a T1 or
fractional-T1 service. Busying out lines in this case would probably be
easier as (I assume) it could be done at the mux.
Mike
--
___________________________________________________________________________
Mike Garvey aka "The Black Cursor" t...@netcom.com
Technical Resources Director mga...@pcmac.com
The PCMAC Consultants "Now with patented Hinder-90" -=- MST3K
John Lundgren
We recently had an addition to a building completed, and the stairwell is
narrow, only about 5 feet wide. The outside of the addition is covered
in tile, which has caused people to give it the name of the bathroom
building, but that's a whole 'nother story. So the teachers let out the
classes, and the stairwell becomes a seething mass of
shoulder-to-shoulder people trying to get down the stairwell.
So, what's this have to do with the previous thread? Well, I'm coming to
that.
In '84, we bought a Gandalf Data PBX, so we could have a limited number
of computer ports service a couple hundred terminals. We didn't expect a
problem, though. BTW, we just took it out of service. Anyone want to
buy a PACX4? 256 ports by 256 terminals.
The teacher in class tells the students to press the enter key to log on,
all at the same time, and presto, instant blocking. It's just that
everything hits the beast at the same time, and poor Gulliver gets dragged
down by the Lilliputians. Like te stairwell, it just couldn't handle the
peak load.
So one of the concepts of a PBX is that it can handle more users than
lines because, on the average, there won't be 100% of the users on at the
same time. Well, this works OK if you're not in a classroom. In the
classroom, everybody does the same thing at the same time. And worse
yet, on the network, everyone boots the same program at the beginning of
class, from the same place on disk, and the poor server just doesn't know
what to do.
So that's the problem with our setting, where training requires a lot of
resources to do certain things in unison. It's sort of like the sewer
plants seeing peaks whenever the commercial breaks come in a big TV
sports event. We recently tried to run our network into a classroom, and
it was too slow. Most of the labs have their own dedicated server with
Netware 3.11 on it. Usually with less than 24 workstations per classroom.
So remember to build your buildings with wider stairwells. That way,
when the Big One (8.0 on the Richter scale) comes, everyone can get out
real quick. What? You say you don't have earthquakes in your area?
Wanna Bet? New York had one not too long ago. Some of the most active
areas on the east coast are in the Carolinas. Here, In So. Cal., we have
not-so-big ones often, but other areas of the country have real big ones
avery couple centuries or so. I think I prefer the former. It's like
being in bed with an elephant. It's good to know when he's going to roll
over.
ObComment: Earthquakes are good for the telco. They cause enough damage
to underground cables to keep the revenues flowing. We recently had a
conduit collapse and most of the pairs go bad. It wasn't that way last
year, before the January 17th shaker we had. We think that was the
reason for the ccollapse.
John Lundgren
Mike Garvey (t...@netcom.com) wrote:
: In a prior missive, jlun...@news.kn.PacBell.COM (John Lundgren) eloquently
: scribed this stuff:
: >[...]
: >
: >As I mentioned below, we have Centrex, and our modems don't go thru a
: >PBX, but just go straight to the CO. We have a PBX, but all the lines
: >going to phones are digital, and a modem can't be used on that kind of
: >line. And since Centrex features are not needed on a modem line, and
: >just costs extra, most of our modem lines are not Centrex, but just
: >straight measured business lines.
: >
: >I can't see why anyone would want to connect a modem to the PBX. The
: >modem doesn't need any features except being on a hunt group, in other
: >words, contention. They mostly receive calls, and don't dial out. And
: >there are often so many modems that the extra cost of PBX lines and SLICs
: >would make it too expensive.
: >
: >[...]
: Also, with tariffs being what they are, if you have need for a LOT of
: modems, it's often cheaper to multiplex your modem lines off of a T1 or
: fractional-T1 service. Busying out lines in this case would probably be
: easier as (I assume) it could be done at the mux.
: Mike
Since the phone company installs and controls the 'pair gain equipment'
such as T1 SLICs, they won't let the subscriber do stuff to their side of
the demarc. They just give you an RJ-21X jack and that's all the closer
you're supposed to go. I don't have any bridging clips that are for
jumpering a pair, so I would probably just punch a piece of xconn wire in
it.
We've had so many main cable pairs from the CO go bad in the last month or
so that I wish they would change to pair gain. At one time, they said
they were going to do it. Our PBX rep said that they have a T1 card that
goes right into the PBX, but Pac Bell can't do it that way because of
tariffs. That's a different way of connecting to the CO, and probably
(presumably) it's less charge to the customer.
John Lundgren
John Higdon (jo...@zygot.ati.com) wrote:
: In article <357hcv$9...@ohlone.kn.PacBell.COM> jlun...@news.kn.PacBell.COM (John Lundgren) writes:
: >We've had so many main cable pairs from the CO go bad in the last month or
: >so that I wish they would change to pair gain. At one time, they said
: >they were going to do it. Our PBX rep said that they have a T1 card that
: >goes right into the PBX, but Pac Bell can't do it that way because of
: >tariffs.
: Call them back. That is baloney. I am getting Pac*Bell dialtone over
: T1. The cost for installation of the T1? Zero. The monthly cost? Zero.
: All I paid was the normal line installation and the normal line monthly
: charges.
: Pac*Bell can, at its discretion, install "invisible DEF" to any
: customer it chooses.
: Squeaky wheels get T1s!
: --
: John Higdon | P.O. Box 7648 | +1 408 264 4115 | FAX:
: jo...@ati.com | San Jose, CA 95150 | 10288 0 700 FOR-A-MOO | +1 408 264 4407
I don't think you understand the whole picture, or you might not have been
so brash. Our district has an agreement with Pac Bell and it is specific
to our district. In other words, custom. We have dial tone from Pac
Bell, but our switch is from David Systems. There is probably something
in the agreement that says that Pac Bell can't step on David Systems
territory. Or that Pac Bell can't offer enhanced services.
I'm not aware of what the agreement says, but it's something like a
contract. And it can't be violated without legal consequences.
John Higdon
>We've had so many main cable pairs from the CO go bad in the last month or
>so that I wish they would change to pair gain. At one time, they said
>they were going to do it. Our PBX rep said that they have a T1 card that
>goes right into the PBX, but Pac Bell can't do it that way because of
>tariffs.
Call them back. That is baloney. I am getting Pac*Bell dialtone over
Chad Leigh
Hi
I brouyght back to Siemens phones from Germany. I hooked them up and
they work fine except they don't ring. I can dial out, answer, etc but no
ringing. What can I do to get them to ring?
Thanks
Chad
--
------------------------- Live Free or Die !----------------------------
What have you done for your country today?
WE'RE trying to defeat Speaker Foley! Please Help!
Macy Hallock
>
>John Higdon (jo...@zygot.ati.com) wrote:
>: In article <357hcv$9...@ohlone.kn.PacBell.COM> jlun...@news.kn.PacBell.COM (John Lundgren) writes:
>
>: >We've had so many main cable pairs from the CO go bad in the last month or
>: >so that I wish they would change to pair gain. At one time, they said
>: >they were going to do it. Our PBX rep said that they have a T1 card that
>: >goes right into the PBX, but Pac Bell can't do it that way because of
>: >tariffs.
>
>: Call them back. That is baloney. I am getting Pac*Bell dialtone over
>: T1. The cost for installation of the T1? Zero. The monthly cost? Zero.
>: All I paid was the normal line installation and the normal line monthly
>: charges.
>
>: Pac*Bell can, at its discretion, install "invisible DEF" to any
>: customer it chooses.
>
>: Squeaky wheels get T1s!
>
>so brash. Our district has an agreement with Pac Bell and it is specific
>to our district. In other words, custom. We have dial tone from Pac
>Bell, but our switch is from David Systems. There is probably something
>in the agreement that says that Pac Bell can't step on David Systems
>territory. Or that Pac Bell can't offer enhanced services.
>
>I'm not aware of what the agreement says, but it's something like a
>contract. And it can't be violated without legal consequences.
This is very strange. Are you saying PacBell has modified their
tarriffed services via a side agreement? Most unlikely.
By definition, all tarriffs are published and equally enforced.
They can be influenced by policy and admin procedures, but that
information must comply with the offer of service within the tarriff.
What I _have_ seen is a telco agency for Centrex, Data or Enhanced
Services make side agreements. I've also seen these agents represent
this as "telco policy". These are not binding to the telco, the telco
is bound by its tarriff, related law and PUC administrative rulings only.
The agent cannot make changes to telco tarriff. Be very sure who you
are really talking to.
I suggest you get this circumstance cleared up in writing. I'd also
insist it be on PacBell letterhead, not someone elses. And I'd seriously
consider involving the PUC in this matter, preferably in writing, as well.
The services of a knowledgable utility/tarriff attorney might be a
very good idea. (Its unlikely you'll find such an attorney locally,
its a specialty more typically found in large cities and state capitals.)
Your current legal counsel may be able to provide a source, if asked.
Sounds like there's enough money and service issues on the table that
it would be worth pushing hard on this, it sounds like you are being
had. This is close to "denial of service" or attempted fraud, IMHO.
--
Macy M. Hallock, Jr. N8OBG +1.216.723.3030 ma...@telemax.com ma...@fms.com
Telemax, Inc. - F M Systems, Inc. 152 Highland Drive Medina, OH 44256 USA
John Higdon
>I don't think you understand the whole picture, or you might not have been
>so brash. Our district has an agreement with Pac Bell and it is specific
>to our district. In other words, custom. We have dial tone from Pac
>Bell, but our switch is from David Systems. There is probably something
>in the agreement that says that Pac Bell can't step on David Systems
>territory. Or that Pac Bell can't offer enhanced services.
Are you in Pac*Bell LEC territory? If so, how does transporting dial
tone to your location over a T span rather than on analog copper pairs
"step on David Systems territory"? DEF is not considered "enhanced
services". It is simply an alternative way of getting POTS to a
customer that happens to be more efficient under certain conditions
(such as when the outside cable plant is at capacity or old and
decrepit).
If you are in someone else's LEC area, the all bets are off. I guess
you are at the mercy of whoever's district you are in.
John Lundgren
John Higdon (jo...@zygot.ati.com) wrote:
: In article <35cmtt$2...@ohlone.kn.PacBell.COM> jlun...@news.kn.PacBell.COM (John Lundgren) writes:
: >I don't think you understand the whole picture, or you might not have been
: >so brash. Our district has an agreement with Pac Bell and it is specific
: >to our district. In other words, custom. We have dial tone from Pac
: >Bell, but our switch is from David Systems. There is probably something
: >in the agreement that says that Pac Bell can't step on David Systems
: >territory. Or that Pac Bell can't offer enhanced services.
: Are you in Pac*Bell LEC territory? If so, how does transporting dial
: tone to your location over a T span rather than on analog copper pairs
: "step on David Systems territory"? DEF is not considered "enhanced
: services". It is simply an alternative way of getting POTS to a
: customer that happens to be more efficient under certain conditions
: (such as when the outside cable plant is at capacity or old and
: decrepit).
: If you are in someone else's LEC area, the all bets are off. I guess
: you are at the mercy of whoever's district you are in.
LEC is Pac Bell, as far as I know. I don't know the details. We have a
meeting once a month with our account reps and a David Sys rep. I know
that the subject of using T1 cards in the switch was brought up by the
David rep, but the rep said that "it wasn't allowed in the tariff." I
have never pressed the issue or brought it up again. The rep has since
retired.
When the people talk in certain sort of cryptic terms in a meeting, I sort
of take it to mean that possibly the reps don't want the customer to know
about the subject. This could be for a number of reasons, one of them
being that it might save the customer money, and, of course, cut their
profits. Our phone bill several years ago was $30,000 a month, so the
stakes might be high.
After reading some of the posts about what people have had done to
them by their telco, I wouldn't be surprised if they are trying to hide
something. But that's not my job. I liked the story by Oppedahl on his
recent experiences with Nynex.
--
John Higdon
>LEC is Pac Bell, as far as I know. I don't know the details. We have a
>meeting once a month with our account reps and a David Sys rep. I know
>that the subject of using T1 cards in the switch was brought up by the
>David rep, but the rep said that "it wasn't allowed in the tariff." I
>have never pressed the issue or brought it up again. The rep has since
>retired.
A very useful piece of advice mentioned here recently was to get anyone
who tells you that the tariff says "so and so" to provide you with the
hard copy. I added that it is helpful to then read along together with
the person. Reps (particularly those who have a fiscal interest in the
transaction) have a tendancy to say whatever is necessary to facilitate
their own agenda. They usually rely on the probability that the
customer is not knowledgable.
John Lundgren
I was reading a survey on telecom, I think it was from
comp.dcom.telecom.tech. It had some replies from colleges with 120, 250
or more modems (!) And some were adding more. The colleges are finding
that it saves them a lot of money if they can get the students to do
their work from a dorm or home computer, and not have to come to a lab on
campus. Many colleges are now installing LAN outlets in their dorms.
John Lundgren (jlun...@news.kn.PacBell.COM) wrote:
OldNick
jlun...@news.kn.PacBell.COM "John Lundgren" writes:
> I was reading a survey on telecom, I think it was from
> comp.dcom.telecom.tech. It had some replies from colleges with 120, 250
> or more modems (!) And some were adding more. The colleges are finding
> that it saves them a lot of money if they can get the students to do
> their work from a dorm or home computer, and not have to come to a lab on
> campus. Many colleges are now installing LAN outlets in their dorms.
Excuse this please .............