Rec Power Level on Cable Modems

[grabbi]

What should the Power be on the Modem?

I have a tech coming out Tuesday because mine is too low, and Im just thinking, anyone else who is having problems should be aware of this problem, because ti could also be happening to them.

Mine:

Downstream Receive Power Level : -5.2 dBmV

---------- Post added at 21:55 ---------- Previous post was at 21:51 ----------

OOPS!

I assume the answer I was requiring is in the Stickys at the top of the Net Forum!

Sorry for not seeing that before! lol

[fatassmichael]

your power level should be fine, the closer to 0 the better, people generally start having problems at above +12 or below -12.

[Nedkelly]

Depends on the modem amits 100 120 200 250 and 255 +5 to -8 but some will say thats not right surfboards -5 to + 5 .Your down streams is alright what is you upstream and the snr :)

[grabbi]

Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -4.7 dBmV
Downstream SNR : 32.9 dB

Upstream Lock : Locked
Upstream Channel ID : 1
Upstream Frequency : 34000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 51.5 dBmV
Upstream Mini-Slot Size : 2

If Im honest, I havent a clue what they mean, but I am being told, from these records, that something is wrong, urgent enough to have a Tech around in 2 days! (shocking!)

What things affect the affected issue?

Is it because I did a self install, and, basically, naff'd up?

---------- Post added at 22:01 ---------- Previous post was at 22:00 ----------

Its a Virgin Media Branded 255 Modem, btw.

[Nedkelly]

Upstream is a bit to high we are seeing a lot of problems with the self install kits ie people putting the splitters the wrong way round :)

[taz10]

this is mine and have no pros at all sb4100

Frequency331000000 Hz LockedSignal to Noise Ratio38 dBQAM256Network Access Control ObjectONPower Level18 dBmV

Channel ID3Frequency29008000 Hz RangedRanging Service ID***Symbol Rate2.560 Msym/sPower Level50 dBmV

[Nedkelly]

Wow a surfboard working at 18dbmv :Yikes:

[taz10]

is that a good thing or not ????????

[Nedkelly]

Not really but as you said you have had no problems with it on the downstream side the closer to 0 is better but sometimes that is not possible.Ie when the qam change came about the modem freq went up by 6 db so a modem that was set at 0 would know be working a +5 or 6

[grabbi]

So, Ned, what would you suggest I do here, then?

Should I have a look at the connection myself, or simply leave for the tech?

Im sure I did everything right, but I could be wrong.

I mean, I know how to put a splitter in! lol

[grabbi]

http://aycu27.webshots.com/image/24146/2006147100489***469_rs.jpg

* where the *** are, replace them with 3 0 7 without the spaces.
The forum wont allow me to put it in as an image or link, for some STRANGE reason! :S

Thats my current setup.

Ive seen 18Mb speeds max. on this modem before, so what has happened since, I dont know.

They said my Head End is booked in for work in the next few weeks because its hitting 99% a lot, so they need to enable some more bandwidth or something.

[piggy]

@grabbi

the only thing left for you to do is to try the modem direct to the pc (power cycle everything) then test again your levels imo look ok

[grabbi]

Ned said the Upstream Power is too high.

It does change frequently, but is staying at around that number.

[Nedkelly]

If it is ok i would leave it and see what happens but if you start getting problems then call in :)

[grabbi]

Well, I was complaining of Speed Problems.

The tech came round and said he'd sort out the power things.

Before a modem reboot:

Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -4.4 dBmV
Downstream SNR : 33.4 dB

Upstream Lock : Locked
Upstream Channel ID : 1
Upstream Frequency : 34000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 52.0 dBmV
Upstream Mini-Slot Size : 2

After a reboot:

Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -4.3 dBmV
Downstream SNR : 34.1 dB

Upstream Lock : Locked
Upstream Channel ID : 1
Upstream Frequency : 34000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 52.0 dBmV
Upstream Mini-Slot Size : 2

[fatassmichael]

It may be my eyes, but all i can see different is the D/S power level raised by 0.1 dBmV and your D/S SNR raised, but more importantly, has your speed increased?

[Acathla]

This thread got me thinking that maybe it has something to do with me having never gotten over 11meg since the 20meg upgrade.

So would a kind sole give me a :tu: or :td: with these:

Blue ntl:250 modem

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 0
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -7.1 dBmV
Downstream SNR : 34.6 dB

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 6
Upstream Frequency : 46384000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 56.0 dBmV
Upstream Mini-Slot Size : 2

[grabbi]

It may be my eyes, but all i can see different is the D/S power level raised by 0.1 dBmV and your D/S SNR raised, but more importantly, has your speed increased?

Nope. Same old...

Nothings changed on any front.

The guy unplugged my modem, replugged it back in, went, and sat in his van for 5 mins.

What he did, I dont know, but early indications show he did nothing.

He said "its a national fault and we all got text messages about it this morning, that 20Mb has a lot of problems they are trying to fix."
He said my power was too high, but he didnt fix it!

---------- Post added at 20:30 ---------- Previous post was at 20:28 ----------

This thread got me thinking that maybe it has something to do with me having never gotten over 11meg since the 20meg upgrade.

So would a kind sole give me a :tu: or :td: with these:

Blue ntl:250 modem

Same modem as me except mines black, and branded VM.

Same problem as me too. Your Up Power is too high, but also your Down power should be at the most 0 and at least -5. My down power is okay, just my up power.

[LaineY]

Upstream should be in between 33 to 55
downstream should be in between -12 to +12

personally ur modems fine m8

---------- Post added at 21:58 ---------- Previous post was at 21:57 ----------

Upstream should be in between 33 to 55
downstream should be in between -12 to +12

personally ur modems fine m8

please note this is only for Telewest sides.. not sure about ntl as i dont deal with ntl issues

[grabbi]

Wed, 08 Aug 2007 00:25:45 GMT

Test 1: 1024K took 1973 ms = 519 KB/sec, approx 4277 Kbps, 4.18 Mbps
Test 2: 1024K took 1662 ms = 616.1 KB/sec, approx 5077 Kbps, 4.96 Mbps
Test 3: 1024K took 1873 ms = 546.7 KB/sec, approx 4505 Kbps, 4.4 Mbps
Test 4: 2048K took 4596 ms = 445.6 KB/sec, approx 3672 Kbps, 3.59 Mbps

Overall Average Speed = approx 4383 Kbps, 4.28 Mbps

Downstream Lock : Locked
Downstream Channel Id : 1
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -3.5 dBmV
Downstream SNR : 33.1 dB

Upstream Lock : Locked
Upstream Channel ID : 1
Upstream Frequency : 34000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 52.0 dBmV
Upstream Mini-Slot Size : 2

DIRECT TO PC from Modem.

Maximum speed from gamefiles.virginmedia.com is 1024 Kbps (2 Simultaneous D/Ls)

Theres a problem, and I want it sorting... Good job I havent been billed for 20Mb yet, coz I wouldnt be paying it...

[J0NO]

My Upstream transmit Power Level is the only thing i worry about on my 255. Right now at 10.40 in the morning its nice at around 40.5 dBmV. But in the evening times it can raise to around 53dBmV. I don't seem to get too many drops.

Is this fluctuation normal and can the 255 modem handle it?

[vmtech]

DIRECT TO PC from Modem.

Maximum speed from gamefiles.virginmedia.com is 1024 Kbps (2 Simultaneous D/Ls)

Theres a problem, and I want it sorting... Good job I havent been billed for 20Mb yet, coz I wouldnt be paying it...

well it looks like your area isnt upgraded yet if thats the most your getting, and you dont pay extra for 20mb

[grabbi]

My area is upgraded.

Ive had 18Mb downstream previous to all this kafuffle.

Network Access : Allowed
Maximum Downstream Data Rate : 20480000
Maximum Upstream Data Rate : 768000
Maximum Upstream Channel Burst : 1600
Maximum Number of CPEs : 1
Modem Capability : Concatenation Enabled, Fragametation Enabled, PHS Disabled

Max Downstream says it all, doesnt it?

I dont care if I pay extra or not. I wont pay for any broadband at this speed... unless I was promised this speed!

In fact, I might even barter with them, and say, I am only paying for the speed I receive...even if it is VIP...