Downstream power level

[evilowl]

Continuing the theme of asking for help on here (http://www.cableforum.co.uk/board/11/33614354-on-demand-problem.html) tonight I thought I would ask about my downstream power level.

For the past few weeks since we were upgraded to 20Mb, my power level has been dropping. We had a repull 3 months ago to try and get some stability as our flat was one of 3 sharing a single cable - the repull made things better for a while but have steadily deteriorated since.

When I log into the CM using the 192.168.100.1 address I see the following:

Downstream Lock : Locked
Downstream Channel Id : 2
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -14.3 dBmV
Downstream SNR : 31.0 dB

Upstream Lock : Locked
Upstream Channel ID : 5
Upstream Frequency : 41584000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 49.8 dBmV
Upstream Mini-Slot Size : 2

When the tech support logs in remotely they see this and say there's no problem

Cable Modem Details

Results of search for cable modem 0014A4xxxxxx
Report Timestamp 2007/04/27@22:36:11
MAC Address Subscriber
Number Billing
Number Franchise Modem Model Service
Level Status DHCP Name CMTS Name
0014A4xxxxxx 5562xxxx 6239xxxxxx COCO NTL Home 250 BUND03 Created bmly-sacmdhcp-1a ubr01lewi
Modem IP Address 10.xxx.xxx.xxx
Ping results from modem : 10 packets sent: 0% lost; 8ms / 21ms / 76ms (Min/Avg/Max)
Modem lease granted at : 24/04/2007 08:47:13
Modem lease expires at : 04/05/2007 20:47:43
CPE IP Address : 82.24.xxx.xxx 82.24.xxx.xxx
Ping results from CPE : 10 packets sent: 0% lost
6ms / 10ms / 36ms
(Min / Avg / Max) 10 packets sent: 100% lost
CPE lease Granted at : 27/04/2007 22:00:04 24/04/2007 08:47:32
CPE lease expires at : 01/05/2007 22:30:08 30/04/2007 08:48:53
CMTS Type Cisco
CMTS MIP 62.253.xxx.xxx
CMTS OS Version 12.3(17b)BC5
cmRxPower +3.5 dB mV
cmStatus registrationComplete
cdxCmtsCmStatusValue onlineTekAssigned
cmSNR +23.8 dB
ccsFlapInsertionFailNum 0
ccsFlapHitNum 16975
ccsFlapMissNum 529
ccsFlapCrcErrorNum 4
ccsFlapPowerAdjustmentNum 0
ccsFlapTotalNum 3
cmTimesOnline 4
cmPercentOnline 99.87 %
cmMinOnline 0d 0h 18m 43s
cmAvgOnline 0d 22h 34m 57s
cmMaxOnline 3d 12h 49m 13s
cmMinOffline 0d 0h 0m 16s
cmAvgOffline 0d 0h 1m 39s
cmMaxOffline 0d 0h 3m 53s
channelSNR +26.2 dB
interfaceDescr Cable5/0-upstream4
interfaceAdminStatus up
interfaceOperStatus up
qosUpstream 768000
qosDownstream 20480000

Also get the ready light flashing occasionally and also regular DNS timeouts to all of the main NTL/Virgin DNS servers, along with intermittent internet access.

In order to pre-empt the typical questions:

Rebooted modem = yes
Restarted PC = yes
Disabled AV = irrelevant
Disabled firewall = not running one
Connected PC to modem directly = yes

Thanks for any insight into the differing results. I'm in South East London if that's any help

[Nedkelly]

Yes that level is not within spec a tech will be needed to see why the level has dropped :) i take it you have a ambit modem :)

[evilowl]

I even sent the lovely non-English fellow I was dealing with a screenshot and they still refused to help saying that their tests showed everything was within acceptable levels

The modem is the blue NTL 250

[Nedkelly]

Check your PM :tu:

[ic2]

I even sent the lovely non-English fellow I was dealing with a screenshot and they still refused to help saying that their tests showed everything was within acceptable levels

The modem is the blue NTL 250

Hi,
been there many times only to be told its within their range (I cannot see their range or know what it is) and when I quote the range discussed on here I am told its acceptable.

my readings at present are:
Downstream SNR : 27.80 dB
Upstream Transmit Power Level : 57.00 dBmv

even quoting those does not help

[Nedkelly]

Yes snr is to low and the upstream is close to 60dbmv :)

[on in an hour!]

Yes snr is to low and the upstream is close to 60dbmv :)
thought it was 61 ned b4 it turned round and tried again (i may b wrong!) ;)

[Nedkelly]

Yes it is 61 dbmv but the ideal range here is 35 to 50 ish ;)

[homealone]

mine says

Downstream Receive Power Level : 7.90 dBmv
Downstream SNR : 33.57 dB
Upstream Transmit Power Level : 49.50 dBmv

it is an ambit 100 on QAM256

[on in an hour!]

mine says

Downstream Receive Power Level : 7.90 dBmv
Downstream SNR : 33.57 dB
Upstream Transmit Power Level : 49.50 dBmv

it is an ambit 100 on QAM256
an ambit 100,are you still putting coal in it to make it work!!! seriously,give em a call,make up some BS,get it swapped,theres been 120,200,250,255 models since then.;)

---------- Post added at 23:37 ---------- Previous post was at 23:36 ----------

Yes it is 61 dbmv but the ideal range here is 35 to 50 ish ;)
same as here fella,woh,weve agreed on something!!! im going to bed..nothing like finishing on a high :D :D :D

[ollie2001]

Don't want to hi-jack this thread, but are mine ok?

Downstream Receive Power Level : -12.8 dBmV
Downstream SNR : 34.1 db

Upstream transmit Power Level : 57dbmv

Been getting pretty slow speeds recently, and my config file is at 20mb! (on the new VM 255 modem btw)

Cheers

[Nedkelly]

Down stream not very good and upstream not very good could be better .You might need a tech to have a look :)

[JamShady]

If I may jump on the bandwagon too, my values are:
Downstream Receive Power Level : 0.4 dBmV
Downstream SNR : 40.0 dB

Upstream is at 58.3 dBmV too which I'm guessing is pretty horrific :(

[Nedkelly]

Upstream is at 58.3 dBmV too which I'm guessing is pretty horrific :([/QUOTE]

Yes that is to high :)

[GPR]

I am on 20meg but only get around 4meg to 5meg, I telephoned TS and they done some tests on my modem and agreed I have a problem as they can see I am only getting 4meg and this friday I have a engineer calling.
Can anyone help me and tell me what sort of things he can do to check and get me to 20meg?.

I have looked into my modem settings and this is what I found
Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 2
Downstream Frequency : 586750000 Hz
Downstream Modulation : QAM64
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : -9.4 dBmV
Downstream SNR : 31.1 dB

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 3
Upstream Frequency : 46384000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 46.0 dBmV
Upstream Mini-Slot Size : 2

Cable Modem Event Log

Wed May 16 15:22:57 2007 Wed May 16 15:22:57 2007 10 Critical(3) 82000500 Started Unicast Maintenance Ranging - No Response received - ...
Time Not Established Time Not Established 7 Critical(3) 68000300 DHCP WARNING - Non-critical field invalid in response.
Time Not Established Time Not Established 16 Critical(3) 82000200 No Ranging Response received - T3 time-out
Wed May 02 16:27:12 2007 Wed May 02 16:27:12 2007 1 Critical(3) 82000400 Received Response to Broadcast Maintenance Request, But no Un...
Wed May 02 16:26:54 2007 Wed May 02 16:26:54 2007 1 Critical(3) 68000100 DHCP FAILED - Discover sent, no offer received
Wed May 02 16:26:40 2007 Wed May 02 16:26:40 2007 3 Critical(3) 82000500 Started Unicast Maintenance Ranging - No Response received - ...
Wed May 02 16:26:37 2007 Wed May 02 16:26:37 2007 1 Critical(3) 68000100 DHCP FAILED - Discover sent, no offer received
Wed May 02 16:26:37 2007 Wed May 02 16:26:37 2007 9 Critical(3) 82000500 Started Unicast Maintenance Ranging - No Response received - ...
Wed May 02 16:26:28 2007 Wed May 02 16:26:28 2007 1 Critical(3) 68000100 DHCP FAILED - Discover sent, no offer received
Wed May 02 16:26:27 2007 Wed May 02 16:26:27 2007 18 Critical(3) 82000500 Started Unicast Maintenance Ranging - No Response received

Cable Modem Operation Configuration

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

Is there anything that looks like the reason why I am only getting around 4meg.

I am connected straight to pc from modem 250 [blue in colour]

Thankyou for taking your time and helping me.

[GPR]

Could someone please take a look at my modem readings to see if there is a problem, V/M Techs have done some tests from there end and say I am only recieving 4meg.
I have V/M engineer coming today and I don t want him to fob me off.
Please help.

[Horace]

I've had huge problems with my connection. I was told by the engineer that visited me a few weeks ago that my power levels were fine. Downstream receive levels tended to fluctuate between -4 and -9. I virtually never got 10meg, most of the time 2meg was the norm or less. Anyway, just had a second engineer visit who stated that my power levels were less than half what they should be. This was after TS claimed my connection was fine and giving me a warning about having to pay £25 if there were no problems found. Everything is running as it should be after months of problems. The first image is how my levels were, the second is how they are now. Downstream seems too high now lol but I'm getting 10meg and I know my power levels will dip to half what they are now so at least my connection will remain stable. This was their last chance before I jumped ship to BE*. Should I have to go through the same routine in future I'll be cancelling faster than you can say "eat my hamster".

http://img180.imageshack.us/img180/9489/ds1cq9.th.png (http://img180.imageshack.us/my.php?image=ds1cq9.png)
http://img185.imageshack.us/img185/1035/ds2po5.th.png (http://img185.imageshack.us/my.php?image=ds2po5.png)

[monkey2468]

Your SNR is much higher now.:)

[BBKing]

Results of search for cable modem 0014A4xxxxxx

This looks like a Blue Tools report to me, and there's an obvious snag in that Blue Tools can't check the downstream power level*. Odd, but true. Hence, everything may well be going swimmingly on the upstream (which they can check), but the downstream may be going to hell in a handcart.

This is obviously an unsatisfactory arrangement and if anyone wants to help me fix it, drop me a PM.

* Or anything else at the modem end beyond pinging it.

[dontpannic]

Can anyone tell me about mine? I had a V+ installed and checked and that was fine, now have a cable running from the wall boc, into a splitter by the V Box, one end of the splitter running upstairs where it splits again between V+ and VM255. V+ sometimes does what my freeview box used to do, and have digital breakup (fairly rarely though)...

Cable Modem Downstream
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 : -7.6 dBmV
Downstream SNR : 32.8 dB

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 1
Upstream Frequency : 34000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 59.0 dBmV
Upstream Mini-Slot Size : 2

This is in Bromley, BR6 area...

Many thanks in advance!

Nick

[J0NO]

Are the Signal levels in >this sticky thread< (http://www.cableforum.co.uk/board/12/26006-cable-modem-signal-levels.html) outdated or is everyone just forgetting to look there?!

[BBKing]

Upstream transmit is extraordinarily high there.

[JamShady]

Upstream is at 58.3 dBmV too which I'm guessing is pretty horrific :(

Yes that is to high :)[/quote]
And weirdly enough, it's back down to 40ish, without any visits from any engineers or whatnot

[Broken Hope]

My power levels are:

Downstream Receive Power Level : 0.1 dBmV
Downstream SNR : 40.5 dB

Upstream transmit Power Level : 56.5 dBmV

I've mentioned to tech's that the upstream seems high compared to what I've read on here but they have always said that the power levels are fine.

[PAYNEARDO]

I have a blue 250 modem and my speeds are normally ok (only have trouble when the rest of us have them). The engineer who installed it did put something on the end of the cabel as he said it was a prob. My power etc are :-

Downstream Lock : Locked
Downstream Channel Id : 3
Downstream Frequency : 402750000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : -12.5 dBmV
Downstream SNR : 34.9 dB


Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 6
Upstream Frequency : 22000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 61.0 dBmV
Upstream Mini-Slot Size : 2

[EssDee]

I have a blue 250 modem and my speeds are normally ok (only have trouble when the rest of us have them). The engineer who installed it did put something on the end of the cabel as he said it was a prob. My power etc are :-

Downstream Lock : Locked
Downstream Channel Id : 3
Downstream Frequency : 402750000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : -12.5 dBmV
Downstream SNR : 34.9 dB


Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 6
Upstream Frequency : 22000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 61.0 dBmV
Upstream Mini-Slot Size : 2

Your Downstream Receive Power looks a bit low. The thing the engineer put on is probably an attenuator. If you took this off the power would likely increase, however if it ain't broke, etc.......

[XFS03]

I have a blue 250 modem and my speeds are normally ok (only have trouble when the rest of us have them). The engineer who installed it did put something on the end of the cabel as he said it was a prob. My power etc are :-

Downstream Lock : Locked
Downstream Channel Id : 3
Downstream Frequency : 402750000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : -12.5 dBmV
Downstream SNR : 34.9 dB


Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 6
Upstream Frequency : 22000000 Hz
Upstream Modulation : QPSK
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 61.0 dBmV
Upstream Mini-Slot Size : 2
Your upstream transmit power level has hit the end stop!
I'm suprised you are getting a reliable connection.


.

[helmutcheese]

Wow, going by Google info months ago, I found on this set up 55 dBmV is max and classed as bad, Im 51 dBmV and was worred but someone here in the know said its ok same as all my other levels.

I know if your cable run is very short from the box on the wall to modem you can get too high a signal so they fit a small attenuator to the cable at modem end normally, I aint sure if this will fix your issue.

[ic2]

Hi,
been there many times only to be told its within their range (I cannot see their range or know what it is) and when I quote the range discussed on here I am told its acceptable.

my readings at present are:
Downstream SNR : 27.80 dB
Upstream Transmit Power Level : 57.00 dBmv

even quoting those does not help

Just had a tech out who was great, even got a phone call to say he was on the way, very impressed. Swapped out the old 120 after checking the version#, he told me they have been swapping loads out in Hemel as they cannot cope with 20mb and struggle with 10mb.

Downloads are up in the 18mb and even going through a Watchguard FW I am getting 12mb now. Readings have not improved much but getting the speeds now:

Downstream SNR : 28.4 dB
Upstream transmit Power Level : 56.5 dBmV