PDA

View Full Version : Acceptable signal strength?



frank
07-07-08, 06:10 PM
Hi,

I seem to have periodic outages with Comcast Internet. I looked at the
signal level while it was happening. Are the following vlaues alarming?

SNR: 26.7dB
Power level: 52.9dBmV
Received signal strenghtl: -19.5 dBmV

$Bill
07-07-08, 07:07 PM
frank wrote:
> Hi,
>
> I seem to have periodic outages with Comcast Internet. I looked at the
> signal level while it was happening. Are the following vlaues alarming?
>
> SNR: 26.7dB

Low - typically in the 30-40 dB range (also depends on chipset QPSK/QAM)

> Power level: 52.9dBmV

High - shouting a bit.

> Received signal strenghtl: -19.5 dBmV

Low - should normally be in the -15 to +15 range (-12 to +12 better - 0 optimal)

I'd have them make a call.

Todd H.
07-08-08, 09:00 AM
"frank" <frank@nospam.com> writes:

> Hi,
>
> I seem to have periodic outages with Comcast Internet. I looked at the
> signal level while it was happening. Are the following vlaues alarming?
>
> SNR: 26.7dB
> Power level: 52.9dBmV
> Received signal strenghtl: -19.5 dBmV


Your upstream power level is pretty high. I generally start seeing
flakey performance and packet loss issues when mine's been over 50.
Mine's at 45dBmV right now.

Your SNR seems a little low. Mine's at 34dB fwiw.

Your received signal strength seems low as well. Mine's at -8dBmV
right now.


Try this at the DOS prompt or Terminal prompt:

ping -t www.google.com


Let it run for a minute or so and hit Ctrl-c.

Look at the (% loss) number towards the end. I bet yours it pretty
substantial. If you mention this packet loss number to the customer
service agent sometimes it can help your case to get a technician out
there to look at the lines. It can be as simple as a cable bent in
too tight an angle in the wall or on the floor, or a connection that
needed to be taken apart and put back together, or replacing a
standard splitter with a directional coupler, or reterminating some
cables with new ends, or several other things that might restore
things to happiness.

But overall, yeah, your signal is iffy enough and your results with it
inconsistent enough that you shouldn't have to live with it. Make em
roll a truck for ya.


Best Regards,
--
Todd H.
http://www.toddh.net/

Todd H.
07-08-08, 09:01 AM
comphelp@toddh.net (Todd H.) writes:

> "frank" <frank@nospam.com> writes:
>
>> Hi,
>>
>> I seem to have periodic outages with Comcast Internet. I looked at the
>> signal level while it was happening. Are the following vlaues alarming?
>>
>> SNR: 26.7dB
>> Power level: 52.9dBmV
>> Received signal strenghtl: -19.5 dBmV
>
>
> Your upstream power level is pretty high. I generally start seeing
> flakey performance and packet loss issues when mine's been over 50.
> Mine's at 45dBmV right now.
>
> Your SNR seems a little low. Mine's at 34dB fwiw.
>
> Your received signal strength seems low as well. Mine's at -8dBmV
> right now.
>
>
> Try this at the DOS prompt or Terminal prompt:
>
> ping -t www.google.com
>
>
> Let it run for a minute or so and hit Ctrl-c.
>
> Look at the (% loss) number towards the end. I bet yours it pretty
> substantial.

Oh, I forgot to mention this loss number should be 0% ... maybe 1%
tops. Any more than that, life really begins to suck. I'd suspect
with your numbers you might be seeing a handful of percent loss, and I
bet when it rains or when it's humid you might be having more problems
than when it's dry out?


If you mention this packet loss number to the customer
> service agent sometimes it can help your case to get a technician out
> there to look at the lines. It can be as simple as a cable bent in
> too tight an angle in the wall or on the floor, or a connection that
> needed to be taken apart and put back together, or replacing a
> standard splitter with a directional coupler, or reterminating some
> cables with new ends, or several other things that might restore
> things to happiness.
>
> But overall, yeah, your signal is iffy enough and your results with it
> inconsistent enough that you shouldn't have to live with it. Make em
> roll a truck for ya.
>
>
> Best Regards,
> --
> Todd H.
> http://www.toddh.net/

--
Todd H.
http://www.toddh.net/

frank
07-08-08, 09:17 AM
Hi,

Currently (with the same signal numbers) my Internet connection seems to
work fine. I did the ping-> resulted in 0% errors.
I noticed a bit error number in my modem: it is 0.028%

"Todd H." <comphelp@toddh.net> wrote in message
news:84wsjwpj8r@news.giganews.com...
> comphelp@toddh.net (Todd H.) writes:
>
>> "frank" <frank@nospam.com> writes:
>>
>>> Hi,
>>>
>>> I seem to have periodic outages with Comcast Internet. I looked at the
>>> signal level while it was happening. Are the following vlaues alarming?
>>>
>>> SNR: 26.7dB
>>> Power level: 52.9dBmV
>>> Received signal strenghtl: -19.5 dBmV
>>
>>
>> Your upstream power level is pretty high. I generally start seeing
>> flakey performance and packet loss issues when mine's been over 50.
>> Mine's at 45dBmV right now.
>>
>> Your SNR seems a little low. Mine's at 34dB fwiw.
>>
>> Your received signal strength seems low as well. Mine's at -8dBmV
>> right now.
>>
>>
>> Try this at the DOS prompt or Terminal prompt:
>>
>> ping -t www.google.com
>>
>>
>> Let it run for a minute or so and hit Ctrl-c.
>>
>> Look at the (% loss) number towards the end. I bet yours it pretty
>> substantial.
>
> Oh, I forgot to mention this loss number should be 0% ... maybe 1%
> tops. Any more than that, life really begins to suck. I'd suspect
> with your numbers you might be seeing a handful of percent loss, and I
> bet when it rains or when it's humid you might be having more problems
> than when it's dry out?
>
>
> If you mention this packet loss number to the customer
>> service agent sometimes it can help your case to get a technician out
>> there to look at the lines. It can be as simple as a cable bent in
>> too tight an angle in the wall or on the floor, or a connection that
>> needed to be taken apart and put back together, or replacing a
>> standard splitter with a directional coupler, or reterminating some
>> cables with new ends, or several other things that might restore
>> things to happiness.
>>
>> But overall, yeah, your signal is iffy enough and your results with it
>> inconsistent enough that you shouldn't have to live with it. Make em
>> roll a truck for ya.
>>
>>
>> Best Regards,
>> --
>> Todd H.
>> http://www.toddh.net/
>
> --
> Todd H.
> http://www.toddh.net/

Todd H.
07-08-08, 10:47 AM
"frank" <frank@nospam.com> writes:

> Hi,
>
> Currently (with the same signal numbers) my Internet connection seems to
> work fine. I did the ping-> resulted in 0% errors.
> I noticed a bit error number in my modem: it is 0.028%


Groovy. You may just be on a bit of a hairy edge. Next time your
connection appears to get flakey, repeat the ping test. I know I've
had experiences in the past where I'd have intermittent degradations
due to weather and such, and things would go to crap with very subtle
changes in the signal numbers.

For example, at 52dBmV upstream, life could be okay on a dry day,
lousy on a wet day.

I'd wait for a crappy day to call the cable company so they can have
something specific like packet loss to hang their hat on for a
justification for a truck roll.

Good luck!

--
Todd H.
http://www.toddh.net/

$Bill
07-08-08, 11:12 AM
frank wrote:
> Hi,
>
> Currently (with the same signal numbers) my Internet connection seems to
> work fine. I did the ping-> resulted in 0% errors.
> I noticed a bit error number in my modem: it is 0.028%

Just for reference, what are your advertised up/down speeds (should be
available where your Tx/Rx/SNR were) ?

And what do you get from a speedtest ?

http://www.broadbandreports.com/speedtest
http://speedtest.net/

Eg: My advertised is 6144/512 (D/L from modem) and right now I'm getting
5635/299 from broadbandreports. And my Tx/Rx/SNR:
Tx Power 50.0 dBmV (slightly on the high side)
Rx Power -4.1 dBmV (good)
Downstream SNR 36.3 dB (good)

frank
07-08-08, 01:31 PM
I have the feeling there are two issues:
1.) the signal
2.) some other issue on the network when my connectivity is bad.

It is difficult to explain 2.) to the support since it happens only so
often.

BTW: my speedtest.net numbers: 6302/989 (with similar signal strenght)

"$Bill" <news@SPAMOLAtodbe.com> wrote in message
news:g503kk$338$1@registered.motzarella.org...
> frank wrote:
>> Hi,
>>
>> Currently (with the same signal numbers) my Internet connection seems to
>> work fine. I did the ping-> resulted in 0% errors.
>> I noticed a bit error number in my modem: it is 0.028%
>
> Just for reference, what are your advertised up/down speeds (should be
> available where your Tx/Rx/SNR were) ?
>
> And what do you get from a speedtest ?
>
> http://www.broadbandreports.com/speedtest
> http://speedtest.net/
>
> Eg: My advertised is 6144/512 (D/L from modem) and right now I'm getting
> 5635/299 from broadbandreports. And my Tx/Rx/SNR:
> Tx Power 50.0 dBmV (slightly on the high side)
> Rx Power -4.1 dBmV (good)
> Downstream SNR 36.3 dB (good)