Cable Modem Levels

[Laffctx]

I just got a new Motorola SB5120 Cable modem a couple weeks ago and these are my normal signal levels.

Frequency 675000000 Hz
Signal to Noise Ratio 34 dB
QAM 256
Network Access Control Object ON
Power Level 0 dBmV The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value
Channel ID 1
Frequency 30496000 Hz
Ranging Service ID 717
Symbol Rate 3.200 Msym/s
Power Level 49 dBmV

But the other night the Upstream Power Level jumped to 62 for about 2 hours. Everything was working fine. And then, it went back to 49. Everything else stayed the same and it hasn't done it since and my speeds are still blazing fast.

Should I be concerned about this .........or is it just one of those "as long as it works dont fix it" type situations?

Thanks for all your help in advance,

Laffctx

 

[Praetor]

Do you have a signal amplifier installed in your house for cable tv? That could be causing that TX to spike.....

<-- hsi field tech.

 

[Big Lar]

Originally posted by: Laffctx
I just got a new Motorola SB5120 Cable modem a couple weeks ago and these are my normal signal levels.

Frequency 675000000 Hz
Signal to Noise Ratio 34 dB
QAM 256
Network Access Control Object ON
Power Level 0 dBmV The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value
Channel ID 1
Frequency 30496000 Hz
Ranging Service ID 717
Symbol Rate 3.200 Msym/s
Power Level 49 dBmV

But the other night the Upstream Power Level jumped to 62 for about 2 hours. Everything was working fine. And then, it went back to 49. Everything else stayed the same and it hasn't done it since and my speeds are still blazing fast.

Should I be concerned about this .........or is it just one of those "as long as it works dont fix it" type situations?

Thanks for all your help in advance,

Laffctx

It is my Understanding, that the "0" means that it isn't showing an actual Power level at all, due to the UL not Ranging.
As Praetor said, could be an amp, or you have too many splitters in the line. Could also be the wrong type of splitter used in the line as well, IMHO.

Larry

 

[Praetor]

Originally posted by: Big Lar

Originally posted by: Laffctx
I just got a new Motorola SB5120 Cable modem a couple weeks ago and these are my normal signal levels.

Frequency 675000000 Hz
Signal to Noise Ratio 34 dB
QAM 256
Network Access Control Object ON
Power Level 0 dBmV The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value
Channel ID 1
Frequency 30496000 Hz
Ranging Service ID 717
Symbol Rate 3.200 Msym/s
Power Level 49 dBmV

But the other night the Upstream Power Level jumped to 62 for about 2 hours. Everything was working fine. And then, it went back to 49. Everything else stayed the same and it hasn't done it since and my speeds are still blazing fast.

Should I be concerned about this .........or is it just one of those "as long as it works dont fix it" type situations?

Thanks for all your help in advance,

Laffctx

It is my Understanding, that the "0" means that it isn't showing an actual Power level at all, due to the UL not Ranging.
As Praetor said, could be an amp, or you have too many splitters in the line. Could also be the wrong type of splitter used in the line as well, IMHO.

Larry

Incorrect. That 0 is the signal level that the modem is getting from your cable provider. For us, anything between +/- 10 is a good thing and 0 (in my opinion) is a very good thing because it's middle of the road and has enough room to go up or down without any noticeable side effects. And that level WILL fluctuate with the temperatures outside and how the maintenance techs are playing with things.

 

[Big Lar]

Originally posted by: Praetor

Originally posted by: Big Lar

Originally posted by: Laffctx
I just got a new Motorola SB5120 Cable modem a couple weeks ago and these are my normal signal levels.

Frequency 675000000 Hz
Signal to Noise Ratio 34 dB
QAM 256
Network Access Control Object ON
Power Level 0 dBmV The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value
Channel ID 1
Frequency 30496000 Hz
Ranging Service ID 717
Symbol Rate 3.200 Msym/s
Power Level 49 dBmV

But the other night the Upstream Power Level jumped to 62 for about 2 hours. Everything was working fine. And then, it went back to 49. Everything else stayed the same and it hasn't done it since and my speeds are still blazing fast.

Should I be concerned about this .........or is it just one of those "as long as it works dont fix it" type situations?

Thanks for all your help in advance,

Laffctx

It is my Understanding, that the "0" means that it isn't showing an actual Power level at all, due to the UL not Ranging.
As Praetor said, could be an amp, or you have too many splitters in the line. Could also be the wrong type of splitter used in the line as well, IMHO.

Larry

Incorrect. That 0 is the signal level that the modem is getting from your cable provider. For us, anything between +/- 10 is a good thing and 0 (in my opinion) is a very good thing because it's middle of the road and has enough room to go up or down without any noticeable side effects. And that level WILL fluctuate with the temperatures outside and how the maintenance techs are playing with things.

Hmmmm that said, this is an excerpt from the page linked below.
"
If a cable modem reports a downstream receive power of exactly 0.0 dB, this means that measurement of downstream power is disabled, and no information is available. In this case, you will need to judge downstream quality by SNR alone."

http://homepage.ntlworld.com/r.../signal.html#goodlevs?

That said, Like I stated before, the UL is not ranged.

 

[Laffctx]

i guess you misunderstood..........i was concerned about the "Upstream Power Level" jumping from 49 to 62 and back again.........it has done this almost every evening.........but it doesn't seem to bother the speed of my cable at all..............i was just wondering if this is something to worry about? I have heard that the Motorola SB5120 Cable Modem can run fine at that Upstream Power Level and I have also heard that it means something is too high.

thanks for all the input,

Laffctx

 

[Big Lar]

The Point is, Your Shown UL Power Levels are not true. So in effect, you shouldn't be concerned.
If you read the page I linked to above, there is some good information on the matter,as well as the Cable FAQ at www.broadbandreports.com

 

[Laffctx]

so all in all........if i am understanding you correctly............your saying as long as everything is functioning normally and i am getting good speed and good service..........there is no real need to be concerned about what these numbers are unless i start seeing signs of something wrong..........like very slow speeds, no signal, loosing and gaining connection or the modem rebooting on its own. "If it isn't broke dont fix it" sort of theory. Maybe i am just gun shy and paying too much attention to the numbers instead of just using common sense.

Thanks,

Laffctx

 

[Big Lar]

Well, Sorta. That the UL is not ranging properly, could be of a concern. Any levels shouldn't flex more than say 1 on a refresh, yours seem to do more than that on a daily basis? Could be you need to call your provider, and check the boot file they send to you.
EDIT; Whoa.... I just noticed that your Download is NOT Locked in, when you got the new modem, did you supply the new Mac Addy to your provider? If not, that may be the problem.