Folded phone line can mess up DSL.

Mike S wrote in news
On 5/12/2018 9:52 PM, Clifford Heath wrote:
On 13/05/18 14:34, Mike S wrote:
On 5/12/2018 8:22 PM, Jason wrote:
In article XnsA8E053B695DAtimothybilyahoocom@
69.16.179.28, says...
Having the wires coiled like that very likely degraded the line
electrical
characteristics to the point that you were getting a lot of
lost/error packets.


Why? Twisted pairs are resistant to interference.

Absolutely, the twisted repairs counteract interference, and each
pair is twisted at a slightly different rate to reduce crosstalk
between the pairs. Here's a simple summary.

https://www.quora.com/How-does-twist...ce-the-interfe
rence-between-the-wires


Yes, but coiling the cable means that pairs (with twist pitch X)
interfere with other turns of themselves (still with pitch X),
so coiling the cable can increase scattering.

Agreed, I used to install DSL and I never did that.


Have you never heard of insulation creep? Under pressure, the plastic
used for modern insulation will slowly flow in such a way as to relieve
that pressure. This can result in direct shorts, changes in spatial
relationships between wires, and other problems. Any of the above will
change the capacitance and inductance of the conductors involved, in a
negative way. Changes in capacitance can cause the digital signals to
round off too rapidly, to the point thay are no longer detectable as
signal pulses at the far end, while changes in inductance can cause
mismatches in impedence that can cause unwanted reflections of the
digital signal, which can also degrade the digital pulses. That is why on
of the first things I was taught about dressing cables was to never pull
cable ties too taut, as that is a prime way of causing both problems,
either in tying up loops or in dressing cable runs.

On 5/13/2018 6:35 AM, Tim wrote:
Mike S wrote in news
On 5/12/2018 9:52 PM, Clifford Heath wrote:
On 13/05/18 14:34, Mike S wrote:
On 5/12/2018 8:22 PM, Jason wrote:
In article XnsA8E053B695DAtimothybilyahoocom@
69.16.179.28, says...
Having the wires coiled like that very likely degraded the line
electrical
characteristics to the point that you were getting a lot of
lost/error packets.


Why? Twisted pairs are resistant to interference.

Absolutely, the twisted repairs counteract interference, and each
pair is twisted at a slightly different rate to reduce crosstalk
between the pairs. Here's a simple summary.

https://www.quora.com/How-does-twist...ce-the-interfe
rence-between-the-wires


Yes, but coiling the cable means that pairs (with twist pitch X)
interfere with other turns of themselves (still with pitch X),
so coiling the cable can increase scattering.

Agreed, I used to install DSL and I never did that.


Have you never heard of insulation creep? Under pressure, the plastic
used for modern insulation will slowly flow in such a way as to relieve
that pressure. This can result in direct shorts, changes in spatial
relationships between wires, and other problems. Any of the above will
change the capacitance and inductance of the conductors involved, in a
negative way. Changes in capacitance can cause the digital signals to
round off too rapidly, to the point thay are no longer detectable as
signal pulses at the far end, while changes in inductance can cause
mismatches in impedence that can cause unwanted reflections of the
digital signal, which can also degrade the digital pulses. That is why on
of the first things I was taught about dressing cables was to never pull
cable ties too taut, as that is a prime way of causing both problems,
either in tying up loops or in dressing cable runs.

That all makes sense. We used Cat5e. On a few occasions the customer
supplied Cat6 for us to run, it had substantial nylon wire guides...
it's clear that a lot of science has gone into ethernet cables.

On 5/11/2018 9:50 PM, Lucifer Morningstar wrote:
On Fri, 11 May 2018 20:34:49 -0400, micky
wrote:

The networking ng is dormant so I thought I'd report this here.

Folded phone line can mess up DSL.


I think a couple years ago when I had 100 feet of phone line but was
only using 40 feet, but wanted to save the whole 100' in one piec, I had
40 feet played out and 60 feet rolled on the spool, and I asked here or
somewhere else if that could cause a slow DSL connection. And iirc the
answer was no, but I'm not sure of that.

So a couple months ago I finally finish installing my home burglar alarm
and I want to connect it to the monitoring company via the phone line.
Since my main phone connection goes in via the second floor, to the
computer on the 2nd floor, I go to the NIC and put a Y connector in it,
adding back the original wire to the basement. Somewhere I have a 6"
piece of phone wire with modular plugs on the end, but I can't find it,
so I put in one of the cords that comes with most phone devices, maybe 8
feet folded up, maybe 6 circle's-worth, squeezed flat.

This is some time between Thursday and Saturday, and Sunday morning I
leave for two months.

I got back two weeks ago today and the house and car were just the way I
left them, and the computer worked fine. For 3 or 4 days. Then it
stopped loading webpages, except very intermittently (so little as to be
unusable), loaded email and newsgrooups only 20% or 30% of the time.
People told me to call Verizon, as if I hadn't thought of that. But
they charge about $60 if it's not their fault, and anyhow, the point is
to figure it out on my own.

Check the NIC. It's popped open. It's under a roof but maybe it got
wet. Doesn't look wet. After a couple days with no better ideas, I
decide to unplug things in the NIC to give them a chance to dry, and
only then I notice the folded phone cord (with the Y-connector). Take
it out, and everything works fine again.

But how come it worked fine for the first 3 or 4 days I was back? And
at least 12 hours, maybe 2 days, before I left?

On similar lines I was using a network cable that was way
longer than needed and the excess was coiled up.
At 1 gigabit packet loss was around 50%.
I replaced it with a much shorter cable and no packet loss.

You may have the clue in your response, "excess was coiled up"
A coil of wire makes an inductor. An inductor is an impedance to high
frequencies.
Years ago, a mobile welder couldn't get his tig welder to work right,
after much consternation, he uncoiled the 75ft of welding cable that was
left on his trailer. The inductance of that coil blocked the high
frequency and it was not helping sustaining the arc.
I don't have an answer why it worked 3 or 4 days.
Mikek

On Fri, 11 May 2018 20:34:49 -0400, micky
wrote:

But how come it worked fine for the first 3 or 4 days I was back? And
at least 12 hours, maybe 2 days, before I left?

Coiling the cord makes something of an inductor. ADSL2+ goes up to
2MHz. If your coil of wire has enough inductance to act as a choke at
2MHz or less, the speed will slow down, but will not quit as it did in
your situation. That's because ADSL has 256 "tones" or channels,
while ADSL2+ has 512.
https://www.hardwaresecrets.com/how-the-adsl-connection-works/2/
The added inductance might cause the higher frequency channels to
drop, but the lower frequency channels and the uplink channels will
continue to work. The ADSL modem also contains an adaptive equalizer
that will partially compensate for the loss in high frequency
channels. You would need to add quite a bit of inductance for the
signal to completely disappear.

From my experience with DSL, most of the problems come from rotten
wire connections and noise coupled from nearby sources. Bad
terminals, mangled connectors, weird adapters, crude microfilters, and
such are all too common. Since the ADSL apparently quit completely, I
would tend to favor a bad connection as the most likely culprit.

It could also be your friendly local telco playing with the DSLAM,
router, or provisioning, which would also make the internet disappear.
I had this happen to me recently which caused me to go through
internet withdrawal for about a week.

There's also the possibility of local interference. Running the phone
line parallel to power lines or other services that use the same
frequency range, such as T1, can cause problems. I had someone in
another newsgroup ask why her internet would disappear at night. I
turned out that when she turned on the lights at night, the associated
noisy light dimmer would couple enough junk into the phone line to
kill the DSL signal. Rewiring the DSL to a "home run" configuration
solve the problem. If the coil of wire were sitting on top of a
length of lamp cord attached to a light dimmer, or switching power
supply low voltage light, or LED light bulb, you're likely to see some
noise coupled to the coil. Even though the balanced pair offers some
noise immunity, the lack of a twisted pair (as in CAT5 cable) in most
flat phone cords, can make the common mode rejection less effective.

I would look for a bad, loose, intermittent, or corroded connection
somewhere in the phone line.

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

On Sun, 13 May 2018 03:27:18 -0400, micky
wrote:

In alt.comp.os.windows-10, on Fri, 11 May 2018 21:41:40 -0400, Jason
wrote:

In article ,
says...
I go to the NIC and put a Y connector in it,

Are there DSL isolators in line where they should be? I
couldn't tell from your post.

No. And it worked fine after I took out the extra cable. That's the
point.

You also moved the extra cable and connectors, which makes me suspect
that an intermittent connection. It takes a minute or three for the
ADSL modem to sync after the carrier returns, which makes cause and
effect type of troubleshooting rather difficult. You could wiggle the
connetions and NOT see any change in the lights on the modem. If you
suspect a bad connection, drag out a roll of CAT5 cable, and plug it
directly into the phone line where it enters the house (MPOE). Also,
disconnect the rest of the house from that might be loading the line.
If that works, your problem is somewhere in your inside wiring. If
the speed, SNR, noise power, and channel levels improve drastically
when you disconnect the hour phone wiring, then you probably are
missing a microfilter, have a microfilter installed backwards, or have
a bad microfilter. Or maybe you need a better microfilter:
http://802.11junk.com/jeffl/pics/dsl/slides/DSL-microfilters.html
(4 inductors are better than 2).

--
Jeff Liebermann
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558

"amdx" wrote in message
news
You may have the clue in your response, "excess was coiled up"
A coil of wire makes an inductor. An inductor is an impedance to high
frequencies.

Would that apply so much to a two-core cable, where at any instant, a
current is flowing one way in one conductor (eg on the way to the appliance)
and the opposite way (on the return) in the other? Would the fact that there
are two conductors tend to reinforce or cancel the effect?

If you have a cable that is too long and don't want to cut it to shorten it,
what is the best way of arranging it so as to avoid/minimise inductance? Is
it better to arrange it in a zig-zag rather than loops?

"NY" wrote in
o.uk:

"amdx" wrote in message
news
You may have the clue in your response, "excess was coiled up"
A coil of wire makes an inductor. An inductor is an impedance to
high
frequencies.

Would that apply so much to a two-core cable, where at any instant, a
current is flowing one way in one conductor (eg on the way to the
appliance) and the opposite way (on the return) in the other? Would
the fact that there are two conductors tend to reinforce or cancel the
effect?

If you have a cable that is too long and don't want to cut it to
shorten it, what is the best way of arranging it so as to
avoid/minimise inductance? Is it better to arrange it in a zig-zag
rather than loops?


At the frequencies DSL works at, inductance is not an issue. More of an
issue is the fact that the wire was kinked. OP doesn't state how
severely, but any kink is going to disrupt the twist pattern, and thus
has the potential to interfere with transmission. The other factor is
that if the kink is severe enough, it can cause partial reflectance of
the signal in the reverse direction, potentially degradeing the signal to
some extent. Since the DSL signal can approach 4mhz at the high end, skin
effect is starting to enter the mix (barely, but there). This is going to
be more noticable in solid core wire, since the single conductor is
larger. In a stranded cable the multiple strands of smaller gauge will
tend to lessen any impact from skin effect. I am going to assume that the
wire is question is stranded as opposed to solid core conductors. In that
case it is entirely possible that one or more of the multiple strands
could actually have been broken by the kink, thus pretty much
guaranteeing some reflection of the signal, with attending degradation.

Granted, the effect of any of the conditions mentioned above will
probably be slight, but they will be additive. The ideal solution would
be to rewire the link to remove any excess wire. The only reason not to
would be that the connection is considered to be only temporary, and even
then I can make a case for not having any excess wire involved.

On 5/17/2018 9:39 PM, Tim wrote:
"NY" wrote in
o.uk:

"amdx" wrote in message
news
You may have the clue in your response, "excess was coiled up"
A coil of wire makes an inductor. An inductor is an impedance to
high
frequencies.

Would that apply so much to a two-core cable, where at any instant, a
current is flowing one way in one conductor (eg on the way to the
appliance) and the opposite way (on the return) in the other? Would
the fact that there are two conductors tend to reinforce or cancel the
effect?

If you have a cable that is too long and don't want to cut it to
shorten it, what is the best way of arranging it so as to
avoid/minimise inductance? Is it better to arrange it in a zig-zag
rather than loops?


At the frequencies DSL works at, inductance is not an issue. More of an
issue is the fact that the wire was kinked. OP doesn't state how
severely, but any kink is going to disrupt the twist pattern, and thus
has the potential to interfere with transmission. The other factor is
that if the kink is severe enough, it can cause partial reflectance of
the signal in the reverse direction, potentially degradeing the signal to
some extent. Since the DSL signal can approach 4mhz at the high end, skin
effect is starting to enter the mix (barely, but there). This is going to
be more noticable in solid core wire, since the single conductor is
larger. In a stranded cable the multiple strands of smaller gauge will
tend to lessen any impact from skin effect. I am going to assume that the
wire is question is stranded as opposed to solid core conductors. In that
case it is entirely possible that one or more of the multiple strands
could actually have been broken by the kink, thus pretty much
guaranteeing some reflection of the signal, with attending degradation.

Granted, the effect of any of the conditions mentioned above will
probably be slight, but they will be additive. The ideal solution would
be to rewire the link to remove any excess wire. The only reason not to
would be that the connection is considered to be only temporary, and even
then I can make a case for not having any excess wire involved.

I agree with previous posters that a bad connector, or a severe kink,
sound like the most likely cause of the problem, in that order.