Downstream Receive Power Level low

[qwqwek]

Guys,

I did a check on my modem today and have found:


Downstream Frequency : 402750000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : -13.9 dBmV
Downstream SNR : 32.8 dB

The sticky suggests that Power level should be -6dBmV. Does this suggest that my connection isnt very good?

btw, i have an Ambit 256 modem.

Cheers

[whydoIneedatech]

Guys,

I did a check on my modem today and have found:

Downstream Modulation : QAM256
Downstream Receive Power Level: -13.9 dBmV
Downstream SNR : 32.8 dB

The sticky suggests that Power level should be -6dBmV. Does this suggest that my connection isnt very good?

btw, i have an Ambit 256 modem.

Cheers
I presume you are an EX-Telewest customer if so please tell us what modem, speed, and Upstream are you getting.

Probably will need to call Tech Support.

[qwqwek]

No, I am an ex-NTL customer. The speed i am supposed to get is 10Mbps. The upstream is as follows:

Upstream Lock : Locked
Upstream Channel ID : 2
Upstream Frequency : 29200000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 58.5 dBmV
Upstream Mini-Slot Size : 2

Is this low?

[moaningmags]

58.5dBmv is way too high and added to that the downstream being low, you definitely need a tech visit.

[whydoIneedatech]

Downstream Receive Power Level : -13.9 dBmV WAY TO LOW


---------- Post added at 22:30 ---------- Previous post was at 22:29 ----------


Upstream transmit Power Level : 58.5 dBmV TOO HIGH


Yes you need to call Tech Support

[qwqwek]

I will call a tech support tomorrow. My mate saw this and was keen on knowing about his connection. How does the following stand?

Downstream Frequency : 402750000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : -10.2 dBmV
Downstream SNR : 33.7 dB

Upstream Channel ID : 4
Upstream Frequency : 37500000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 55.0 dBmV
Upstream Mini-Slot Size : 2

He is also on ex-Ntl area.

[whydoIneedatech]

I will call a tech support tomorrow. My mate saw this and was keen on knowing about his connection. How does the following stand?

Downstream Frequency : 402750000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : -10.2 dBmV
Downstream SNR : 33.7 dB

Upstream Channel ID : 4
Upstream Frequency : 37500000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 55.0 dBmV
Upstream Mini-Slot Size : 2

He is also on ex-Ntl area.
Downstream to low he needs to call as well, does he live in the same street as you.

[Axegrinder]

Downstream Receive Power Level : -10.2 dBmV = Too Low

Upstream transmit Power Level : 55.0 dBmV = Borderline ;)


EDIT Beaten :o:

[qwqwek]

Ok guys, i gave a call to the customer service. They suggest that i should call them when i get a disconnect next time. I am not getting big disconnects at the moment. Should i do a couple of speed tests to verify if this low power level is really causing an issue. Or should i take a chill pill and not bug VM any more?

What effect do these low power levels have anyway?

[whydoIneedatech]

Ok guys, i gave a call to the customer service. They suggest that i should call them when i get a disconnect next time. I am not getting big disconnects at the moment. Should i do a couple of speed tests to verify if this low power level is really causing an issue. Or should i take a chill pill and not bug VM any more?

What effect do these low power levels have anyway?
Best calling between 0800 and 2000 tomorrow, it will cause possible speed issues and disconnections.

[VMboy]

I have the opposite problem in that my Cable Modem Downstream Level is too high.

Downstream Receive Power Level : 12.1 dBmV
Downstream SNR : 38.2 dB

Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 44.5 dBmV

[Ignitionnet]

19-10-2008, 22:34

[Sephiroth]

Ok guys, i gave a call to the customer service. They suggest that i should call them when i get a disconnect next time. I am not getting big disconnects at the moment. Should i do a couple of speed tests to verify if this low power level is really causing an issue. Or should i take a chill pill and not bug VM any more?

Downstream Frequency : 402750000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : -13.9 dBmV
Downstream SNR : 32.8 dB

Upstream Channel ID : 2
Upstream Frequency : 29200000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 58.5 dBmV
Upstream Mini-Slot Size : 2

What effect do these low power levels have anyway?

Your question wasn't answered - so here's my perpective. Now, you javen't told us what you're experiencing. I'd wind my neck out and say you're not experiencing much by way of service. If you are, I'd ne amazed since your modem is simply not set up within the DOCIS specification wo work within the numbers you've given.

With a lowish SNR, I would expect the CMTS to have to drive higher power than what is frankly a ridiculous -13.9 dBmv. The modem is supposed to normalise at 0 dBmv, when it receives data at a certain power level. When it's -13.9 dBmv, the received power is so far below what the modem is set up for that it might as well be switched off.

If you then match that to the upstream side, you share common infrastructure with downstream up to the street cabinet. If there is a poor SNR downstream on this section, then there is a poor SNR seen by the CMTS at the VM end. Hence your highish upstream power.

So my first port of call on this would be to look at your coax cable - screwed in properly at both ends? Not too long? Not kinked? Ourside wall box not corroded inside with damp?

The engineer would check the coax back to the street box where the same problem can be found there or en-route at the amplifiers etc.

Your modem could have gone to Ludwig, of course. These things are never simple and it could all be wrong at the CMTS end. We don't see their data about your line. But what I've said is how it could be seen from the forum by people hundreds of miles away from you.

Hope that helps.

[Ignitionnet]

With a lowish SNR, I would expect the CMTS to have to drive higher power than what is frankly a ridiculous -13.9 dBmv. The modem is supposed to normalise at 0 dBmv, when it receives data at a certain power level. When it's -13.9 dBmv, the received power is so far below what the modem is set up for that it might as well be switched off.

Wind that neck back in, the CMTS does not vary its' transmit power it's fixed :p:

Probably a loose connector somewhere to be honest.

[Sephiroth]

Wind that neck back in, the CMTS does not vary its' transmit power it's fixed :p:

Probably a loose connector somewhere to be honest.

I expressed that badly. The power received at the modem after all the impedances have been overcome should not be at the silly level reported. And, of course, my main suspect is the cable as you suggest.

As for winding out my neck - that's on the OP's experience. The OP hasn't told us anything about that. Nor has the OP said whether the other person with similar stats lives in the same street which then changes the picture unless two screws (besides yours and mine) are loose.

[Ignitionnet]

*Lends OP a guillotine... you know you want to OP :D

That assumes he reads it of course. You did spot Seph that this post was a necromancy job by VMBoy? :)

19-10-2008, 22:34

[Sephiroth]

*Lends OP a guillotine... you know you want to OP :D

That assumes he reads it of course. You did spot Seph that this post was a necromancy job by VMBoy? :)

Too deep for me BBings. Is he Ulysses or Hades?

[Peter_]

Too deep for me BBings. Is he Ulysses or Hades?
This thread that VMboy has unearthed in Burke and Hare mode is almost 14 months old and you are answering questions from that thread.:D:D:D

[Sephiroth]

I hate it when that happens!