SB5120 & Comcast Woes

SB5120 & Comcast Woes
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Subject Author Date
SB5120 & Comcast Woes mediumhappy 12-18-2006
Posted by Timothy Daniels on December 19, 2006, 1:14 pm
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It varies around 50-51 dBmV. The low Transmit level may be low due to
a high Receive level (assuming that "X dBmV" means "minus X dBmV").

*TimDaniels*

"Ed Nielsen" wrote:
> 15dBmV at the downstream is pretty high. I would sure like to see that
> down below 0. What is your transmit level?
>
>
> CIAO!
>
> Ed N.
>
> Timothy Daniels wrote:
>> The modem web page AND Tier 3 interrogations to the modem show a
>> low receive signal level (modem reports 15 dBmV)
>
>> *TimDaniels*

Pure Networks
Posted by Todd H. on December 19, 2006, 3:49 pm
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> It varies around 50-51 dBmV. The low Transmit level may be low due to
> a high Receive level (assuming that "X dBmV" means "minus X dBmV").

>=50dBmV on transmit is your problem. Or comcast's problem. :-) That
needs to be in the 40's or high 30's or it'll be packetloss city in my
experience, and you'll have horribly unreliable service.

How many splits occur before that cable line gets to your modem?

I've had my provider out here several times and I think we vfinally
got it figured out here. DC-9 directional couplers were needed to get
returnable signal to my office. These have an insertion loss of half
a dB on the through leg.

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

Posted by Timothy Daniels on December 19, 2006, 3:38 pm
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"Ed Nielsen" wrote:
> Timothy Daniels wrote:
>> The modem web page AND Tier 3 interrogations to the modem show a
>> low receive signal level (modem reports 15 dBmV)
>>
>> *TimDaniels*
>
> 15dBmV at the downstream is pretty high. I would sure like to see that
> down below 0. What is your transmit level?


The line technicians were by today, and they said the signal level
on the downstream side (coming into our property) was a bit high,
so they padded it down by 4-5 dB. Now the modem is reporting a
downstram signal level of 9 dBmV and an upstream signal level of
47 dBmV. It had been 15-17 downstream and 50-52 upstream.
I asked the tech who adjusted our amp if those numbers meant
NEGATIVE dB, but he said no (which may still not mean anything).

The bottom line is that the speeds have increased a bit, but it's
not really obvious due to the high variance from test to test. Tracerts
are still showing timeouts, and InternetFrog.com is showing "Quality
of Service" levels ranging between 9% and 50%, i.e. high retransmission
rates, and the VOIP test indicates that there would be lots of dropouts
and pauses. I believe it's due to congestion in the RoadRunner network.

*TimDaniels*



Posted by Bill G on December 19, 2006, 4:33 pm
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On Tue, 19 Dec 2006 12:38:09 -0800, "Timothy Daniels"

>"Ed Nielsen" wrote:
>> Timothy Daniels wrote:
>>> The modem web page AND Tier 3 interrogations to the modem show a
>>> low receive signal level (modem reports 15 dBmV)
>>>
>>> *TimDaniels*
>>
>> 15dBmV at the downstream is pretty high. I would sure like to see that
>> down below 0. What is your transmit level?
>
>
> The line technicians were by today, and they said the signal level
>on the downstream side (coming into our property) was a bit high,

Yes, of course. The downstream value you posted WAS high and Ed
pointed that out, even though you initially said you thought it was
low. It should be no surprise that the line tech confirmed that it was
high and therefore padded it down to a more reasonable level.


>so they padded it down by 4-5 dB. Now the modem is reporting a
>downstram signal level of 9 dBmV and an upstream signal level of
>47 dBmV. It had been 15-17 downstream and 50-52 upstream.

The new values look great.

>I asked the tech who adjusted our amp if those numbers meant
>NEGATIVE dB, but he said no (which may still not mean anything).

No, they mean POSITIVE dB, referenced to 1 mV, i.e., signal levels
that were too high, not too low. You seem to be predisposed to
thinking your levels were too low. (??)


> The bottom line is that the speeds have increased a bit, but it's
>not really obvious due to the high variance from test to test. Tracerts
>are still showing timeouts, and InternetFrog.com is showing "Quality
>of Service" levels ranging between 9% and 50%, i.e. high retransmission
>rates, and the VOIP test indicates that there would be lots of dropouts
>and pauses. I believe it's due to congestion in the RoadRunner network.

What leads you to believe it's due to congestion in the RoadRunner
network?

--
Bill

Posted by Todd H. on December 19, 2006, 10:48 pm
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> "Ed Nielsen" wrote:
> > Timothy Daniels wrote:
> >> The modem web page AND Tier 3 interrogations to the modem show a
> >> low receive signal level (modem reports 15 dBmV)
> >>
> >> *TimDaniels*
> >
> > 15dBmV at the downstream is pretty high. I would sure like to see
> > that down below 0. What is your transmit level?
>
>
> The line technicians were by today, and they said the signal level
> on the downstream side (coming into our property) was a bit high,
> so they padded it down by 4-5 dB. Now the modem is reporting a
> downstram signal level of 9 dBmV and an upstream signal level of
> 47 dBmV. It had been 15-17 downstream and 50-52 upstream.
> I asked the tech who adjusted our amp if those numbers meant
> NEGATIVE dB, but he said no (which may still not mean anything).
>
> The bottom line is that the speeds have increased a bit, but it's
> not really obvious due to the high variance from test to test. Tracerts
> are still showing timeouts, and InternetFrog.com is showing "Quality
> of Service" levels ranging between 9% and 50%, i.e. high retransmission
> rates, and the VOIP test indicates that there would be lots of dropouts
> and pauses. I believe it's due to congestion in the RoadRunner
> network.

Weather does affect these numbers in my experience.

Yeah, upstream power level is nearly always in positive dBmV.
Downstream powerlevels yo ucan see in + and - territory. You had one
seriously hot signal before. My downstream is -5.5dBmV right now for
instance. upstream 43.50 dBmV.

Congestion shouldn't affect your signal levels. It will affect
throughput and packetloss perhaps, but these signal levels it should
not affect at all.

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

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