Signal strength

[Walter R.]

Is there a way I can determine signal strength at my cable modem from my
computer?

I had a problem with signal strength which was resolved by the technician.
He pulled up a program on my computer that gave him the signal strength. I
forgot to ask him how he did that.

Does anyone know?

[John W Montgomery]

http://192.168.100.1/

[Walter R.]

Thank you, John

[Walter R.]

Forgot to ask you, John:

For future reference (the system is working fine, now):

What are considered normal Signal to Noise Ratios (+30 db?) and the Power
Level (-15 dbm)?

Thanks

[John W Montgomery]

Normal level range is:
Signal to noise 35 to 40
Downstream power level 0 to -5
Upstream power level 30 to 50

[Scott Lindner]

Thanks for that post. This thread is a keeper!

[Scott Lindner]

That's too easy. Thanks for sharing that.

Since I'm having troubles at home I'm curious what are considered to be
within spec and on the boundaries of the spec. My cable modem is reading
the following:

Downstream
Freq. 615MHz
SNR 36.5dB (estimated because it jumps between 36 & 37)
Power Level -3dBmV

Upstream
Channel 5
Freq. 30.384MHz
Power Level 36dBmV

[stevech]

those look like very good numbers. Watch the upstream - see if it wanders up
to 50 dBmV at times. Can happen, due to interference/ingress.
What are your trouble symptoms? Generally, if the modem lights don't
misbehave, the signal levels are rather unimportant.

Post by Scott Lindner
That's too easy. Thanks for sharing that.
Since I'm having troubles at home I'm curious what are considered to be
within spec and on the boundaries of the spec. My cable modem is reading
Downstream
Freq. 615MHz
SNR 36.5dB (estimated because it jumps between 36 & 37)
Power Level -3dBmV
Upstream
Channel 5
Freq. 30.384MHz
Power Level 36dBmV

[Scott Lindner]

Post by stevech
those look like very good numbers. Watch the upstream - see if it wanders up
to 50 dBmV at times. Can happen, due to interference/ingress.
What are your trouble symptoms? Generally, if the modem lights don't
misbehave, the signal levels are rather unimportant.

The signal lights drop in and out sometimes. This was due to an RR router
change. However, recently it hasnt't been as bad. What gets me is that the
metrics are very good in my situation. What else could be wrong?

Thankfully, it isn't bad enough for me to wait for techs to come out. We'll
see what my wife has to say about that though. She was really upset when we
were having the most troubles.

Scott

[Scott Lindner]

Post by stevech
those look like very good numbers. Watch the upstream - see if it wanders up
to 50 dBmV at times. Can happen, due to interference/ingress.
What are your trouble symptoms? Generally, if the modem lights don't
misbehave, the signal levels are rather unimportant.

This is odd. I've been suffering dropouts much more frequently starting a
little over a day ago. This is the same trouble I've been having for three
weeks. At the moment I'm writing this I have only the power indicator on
the cable modem, every once in a while the receive will start flashing and
drop back down to power. For a little while I was able to read the Signal
levels on the cable modem. They aren't much different than the ones I
already posted. But now after it's been dead for a while the page will not
load at all. Then in an instant all indicators go full on after being down
for about two minutes and I can read the page again. Is this a sign of a
failing modem?

Scott

[Vagabond Software]

Post by Scott Lindner
That's too easy. Thanks for sharing that.

That's easy for you to say, I pointed my browser to the recommended address
and was denied access. Apparently, it does not work with the modems that
come with Internet Phone service.

Carl

[Scott Lindner]

Post by Vagabond Software
That's easy for you to say, I pointed my browser to the recommended address
and was denied access. Apparently, it does not work with the modems that
come with Internet Phone service.

Could it be an internal routing issue? Possibly a firewall or netmask
issue?

[Vagabond Software]

Post by Vagabond Software

Post by Vagabond Software
That's easy for you to say, I pointed my browser to the recommended

address

Post by Vagabond Software
and was denied access. Apparently, it does not work with the modems that
come with Internet Phone service.

Could it be an internal routing issue? Possibly a firewall or netmask
issue?

I was getting ready to reply with this big long response about how that
couldn't be the problem, and I've checked all that, blah blah blah...

It seems the Power Failure in Tierrasanta earlier this afternoon has done
wonders for my modem. I can now hit it with my browser.

Here are my numbers:

Downstream
Freq/Power: 615.000 MHz -11 dBmV
Signal to Noise Ratio: 34 dB
Modulation: QAM256

--------------------------------------------------------------------------------
Upstream
Freq/Power: 32.000 MHz 48 dBmV
Channel Type: DOCSIS 1.x (TDMA)

Symbol Rate: 2560 kSym/sec

Modulation: QAM16

Regards,

Carl

[v***@despammed.com]

Just curious.... What area of Tierrasanta are you in? I'm in Villa Monterey, I
was home all day, and we didn't have a failure today.

Post by Vagabond Software

Post by Vagabond Software

Post by Vagabond Software
That's easy for you to say, I pointed my browser to the recommended

address

Post by Vagabond Software
and was denied access. Apparently, it does not work with the modems that
come with Internet Phone service.

Could it be an internal routing issue? Possibly a firewall or netmask
issue?

I was getting ready to reply with this big long response about how that
couldn't be the problem, and I've checked all that, blah blah blah...
It seems the Power Failure in Tierrasanta earlier this afternoon has done
wonders for my modem. I can now hit it with my browser.
Downstream
Freq/Power: 615.000 MHz -11 dBmV
Signal to Noise Ratio: 34 dB
Modulation: QAM256
------------------------------------------------------------------------------

--

Post by Vagabond Software
Upstream
Freq/Power: 32.000 MHz 48 dBmV
Channel Type: DOCSIS 1.x (TDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM16
Regards,
Carl

[Vagabond Software]

Post by v***@despammed.com
Just curious.... What area of Tierrasanta are you in? I'm in Villa Monterey, I
was home all day, and we didn't have a failure today.

I'm in Porto-Fino, across from Serra High School. I believe the whole
neighborhood was down for about 3 hours. I know it started around 4 PM
because I was using Remote Desktop from work and suddenly could no longer
reach the client.

I immediately assumed either Road Runner was down or we had YET ANOTHER
power failure.

Regards,

Carl

[stevech]

upstream at 48dBmV is high. You have a different modem than I do. Mine is
designed to go no more than about 52dBmV.
In my experience, if yours is at 48, and you check it often, you'll see it
vary by 6 or so. So the question is what is the average? If 48 is a peak,
not average, this marginally OK.
Your downstream at -11 is somewhat low; ideally closer to zero.

Is you cable modem fed from the first tap on you cable after it enters the
house?
Is that tap a two-way? It should not be a 3 or 4 way.
There should be no amplifier between your cable modem and the incoming
cable. If your house has an amp, wire it downstream of the cablem modem's
tap.

Steve

Post by Vagabond Software

Post by Vagabond Software

Post by Vagabond Software
That's easy for you to say, I pointed my browser to the recommended

address

Post by Vagabond Software
and was denied access. Apparently, it does not work with the modems that
come with Internet Phone service.

Could it be an internal routing issue? Possibly a firewall or netmask
issue?

I was getting ready to reply with this big long response about how that
couldn't be the problem, and I've checked all that, blah blah blah...
It seems the Power Failure in Tierrasanta earlier this afternoon has done
wonders for my modem. I can now hit it with my browser.
Downstream
Freq/Power: 615.000 MHz -11 dBmV
Signal to Noise Ratio: 34 dB
Modulation: QAM256
--------------------------------------------------------------------------

------

Post by Vagabond Software
Upstream
Freq/Power: 32.000 MHz 48 dBmV
Channel Type: DOCSIS 1.x (TDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM16
Regards,
Carl

[Vagabond Software]

Post by stevech
upstream at 48dBmV is high. You have a different modem than I do. Mine is
designed to go no more than about 52dBmV.
In my experience, if yours is at 48, and you check it often, you'll see it
vary by 6 or so. So the question is what is the average? If 48 is a peak,
not average, this marginally OK.
Your downstream at -11 is somewhat low; ideally closer to zero.
Is you cable modem fed from the first tap on you cable after it enters the
house?
Is that tap a two-way? It should not be a 3 or 4 way.
There should be no amplifier between your cable modem and the incoming
cable. If your house has an amp, wire it downstream of the cablem modem's
tap.
Steve

Here are my numbers from this morning:

Downstream
Freq/Power: 615.000 MHz -9 dBmV
Signal to Noise Ratio: 34 dB
Modulation: QAM256
--------------------------------------------------------------------------------
Upstream
Freq/Power: 32.000 MHz 48 dBmV
Channel Type: DOCSIS 1.x (TDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM16

The cabling comes in from the alley into the roof. What happens up there, I
cannot say, but I wouldn't be surprised if there were a splitter up there.
The cabling out of the wall in the main room is exactly how the TW
installation tech left it. From the wall, the cable goes into a splitter.
One side goes to our digital cable box and the other side run about 50 feet
to our cable modem in the office.

Getting the digital cable, modem, and phone was a great deal for the money,
but we have been very disappointed. The problems with the Internet access
have settled down tremendously of late, but the quality of our movie channel
package is terrible. Every few seconds, the picture distorts, halts, and
pauses while the audio may or may not continue playing. The movie channels
are unwatchable in the late afternoons and evenings because of this problem.

Thanks for the reply.

Carl

[Frank ess]

Post by Scott Lindner

Post by stevech
upstream at 48dBmV is high. You have a different modem than I do.
Mine is designed to go no more than about 52dBmV.
In my experience, if yours is at 48, and you check it often, you'll
see it vary by 6 or so. So the question is what is the average? If
48 is a peak, not average, this marginally OK.
Your downstream at -11 is somewhat low; ideally closer to zero.
Is you cable modem fed from the first tap on you cable after it
enters the house?
Is that tap a two-way? It should not be a 3 or 4 way.
There should be no amplifier between your cable modem and the
incoming cable. If your house has an amp, wire it downstream of the
cablem modem's tap.
Steve

Downstream
Freq/Power: 615.000 MHz -9 dBmV
Signal to Noise Ratio: 34 dB
Modulation: QAM256
--------------------------------------------------------------------------------
Upstream
Freq/Power: 32.000 MHz 48 dBmV
Channel Type: DOCSIS 1.x (TDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM16
The cabling comes in from the alley into the roof. What happens up
there, I cannot say, but I wouldn't be surprised if there were a
splitter up there. The cabling out of the wall in the main room is
exactly how the TW installation tech left it. From the wall, the
cable goes into a splitter. One side goes to our digital cable box
and the other side run about 50 feet to our cable modem in the
office.
Getting the digital cable, modem, and phone was a great deal for the
money, but we have been very disappointed. The problems with the
Internet access have settled down tremendously of late, but the
quality of our movie channel package is terrible. Every few
seconds,
the picture distorts, halts, and pauses while the audio may or may
not continue playing. The movie channels are unwatchable in the
late
afternoons and evenings because of this problem.

One of our neighbors got the movie package. For the first two months
the cable guy's van was parked out front for hours at a time, two or
three days a week. Now it's just once a week. I guess that's an
improvement.

[stevech]

Upstream is at 48 which is high (irregular).
Get the TW tech to measure the downstream and test the upstream at the cable
entry to your premesis. If the upstream is much less than 48 dBmV (like in
the mid-30's), then you have line losses/splitters to deal with in your
premesis. If he says the level is still near 48, it's either TW's problem or
a problem with the coax from your premesis to their demarcation point.

I fought this problem for a long, long time and found a solution myself,
though TW techs were here 10 times or so.

Post by Scott Lindner
Downstream
Freq/Power: 615.000 MHz -9 dBmV
Signal to Noise Ratio: 34 dB
Modulation: QAM256
--------------------------------------------------------------------------

------

Post by Scott Lindner
Upstream
Freq/Power: 32.000 MHz 48 dBmV
Channel Type: DOCSIS 1.x (TDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM16
The cabling comes in from the alley into the roof. What happens up there, I
cannot say, but I wouldn't be surprised if there were a splitter up there.
The cabling out of the wall in the main room is exactly how the TW
installation tech left it. From the wall, the cable goes into a splitter.
One side goes to our digital cable box and the other side run about 50 feet
to our cable modem in the office.
Getting the digital cable, modem, and phone was a great deal for the money,
but we have been very disappointed. The problems with the Internet access
have settled down tremendously of late, but the quality of our movie channel
package is terrible. Every few seconds, the picture distorts, halts, and
pauses while the audio may or may not continue playing. The movie channels
are unwatchable in the late afternoons and evenings because of this problem.
Thanks for the reply.
Carl

[Scott Lindner]

Post by Vagabond Software
I was getting ready to reply with this big long response about how that
couldn't be the problem, and I've checked all that, blah blah blah...
It seems the Power Failure in Tierrasanta earlier this afternoon has done
wonders for my modem. I can now hit it with my browser.

I guess that's good news, right? :)

[Walter R.]

Uplink
SNR steady at 32
Power Level -14 AM, -18 PM

Downlink
Power Level +45 steady

Is the uplink power level ok?
Sometimes I lose connectivity: the power and receive lights are steady, the
Send is flashing
Most of the time, though, the internet works OK: All lights on and Activity
flickering

Anything to worry about?
--
Walter
www.rationality.net
-

Post by Walter R.
Is there a way I can determine signal strength at my cable modem from my
computer?
I had a problem with signal strength which was resolved by the technician.
He pulled up a program on my computer that gave him the signal strength. I
forgot to ask him how he did that.
Does anyone know?
--
Walter
www.rationality.net
-

[John W Montgomery]

You reversed your up and down. Your downstream is weak. You need a visit by techs to check it out!

[stevech]

Walter
flashing send is related to your upstream not being heard properly at the
cable system's head-end. Weak signal.
Those numbers, below, seem backwards to me. What modem do you have?
"-14 AM" is this a typo? I've seen the downstream at xx dBmV where this
ranges -15 to +2 or so.
The number you have for Downlink is what I've seen for the upstream
(uplink).

The upstream at 45dBmV is somwhat the max. Hopefully, the average is less
that 45.
The TW cable system head-end commands the modem to increase/decrease the
upstream level to balance the system. This is called ranging.

Post by Walter R.
Uplink
SNR steady at 32
Power Level -14 AM, -18 PM
Downlink
Power Level +45 steady
Is the uplink power level ok?
Sometimes I lose connectivity: the power and receive lights are steady, the
Send is flashing
Most of the time, though, the internet works OK: All lights on and Activity
flickering
Anything to worry about?
--
Walter
www.rationality.net
-

Post by Walter R.
Is there a way I can determine signal strength at my cable modem from my
computer?
I had a problem with signal strength which was resolved by the technician.
He pulled up a program on my computer that gave him the signal strength. I
forgot to ask him how he did that.
Does anyone know?
--
Walter
www.rationality.net
-