Edinburgh Slow Speeds

[Sephiroth]

You seem to be getting into some spats, VMboy!

Anyway, like said, 10.6dBmv is not generally recognised as a problem free receive power level based on recorded experiences. In your first post you said that a couple of days ago things were normal after 10 pm. We don't know what your power levels were then.

The receive power level starts from the CMTS at a fixed number - a much higher level than your modem reports. Fibre, cable, junctions, splitters and so on all provide impedance (to keep it simple) and by the time it reaches you it should be a low value - ideally 0dBmv. There are tolerances for integrity depending on how your data is packed (the QAM value) and that physically stretches to +/- 10dBmv.

If your receive power level is always what you've reported, then there is stability in the impedances and the only problem you may ultimately face is a modem that objects to being hit with more than 10 dBmv.

I suppose if you're directly connected to an optical node at the regional hub rather than going through a cabinet, your receive power level could be higher than the normal user; in that case the engineer would fit a forward path attenuator to your modem because it doesn't need 10.6 dBmv to give you a stable service.

Maybe the above explanation rows back somewhat from my earlier "much too high" suggestion. But I think you should get it attenuated and on this occasion it may not be (yet) the cause of your poor experience.

[VMboy]

Thanks Sephiroth,

Here is my current modem downstream info, and also my most current speed test being a direct internet connection without going through a proxy.



Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 4
Downstream Frequency : 331000000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : 10.4 dBmV
Downstream SNR : 38.6 dB

---------- Post added at 00:54 ---------- Previous post was at 00:46 ----------

Just another test with a direct connection using Firefox.



And another going through a proxy that is needed for the anti virus program, notice the speeds are much less.



And the modem info at the time.

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 4
Downstream Frequency : 331000000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 5360.537 Ksym/sec
Downstream Interleave Depth : taps32Increment4
Downstream Receive Power Level : 10.5 dBmV
Downstream SNR : 38.8 dB

[Sephiroth]

I'm on 20Mbps and these are my readings:

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 31
Downstream Frequency : 443000000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : 2.9 dBmV
Downstream SNR : 37.5 dB

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 4
Upstream Frequency : 45800000 Hz
Upstream Modulation : QAM16
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 37.0 dBmV
Upstream Mini-Slot Size : 2



So at 01:00 I'm only getting 5.66 Mb/s on the basis of speedtest.net @ Birmingham (and I'm not bothered). So on this occasion we can't pin it down to your high receive power level - but it needs attenuating anyway.

There's work going on in the network. That much is now clear and that's affecting us both.

Oh - and about that proxy server - you surely aren't gonna continue with that AV method?

[VMboy]

Originally Posted by Sephiroth

I'm on 20Mbps and these are my readings:

Cable Modem Downstream
Downstream Lock : Locked
Downstream Channel Id : 31
Downstream Frequency : 443000000 Hz
Downstream Modulation : QAM256
Downstream Symbol Rate : 6952 Ksym/sec
Downstream Interleave Depth : taps12Increment17
Downstream Receive Power Level : 2.9 dBmV
Downstream SNR : 37.5 dB

Cable Modem Upstream
Upstream Lock : Locked
Upstream Channel ID : 4
Upstream Frequency : 45800000 Hz
Upstream Modulation : QAM16
Upstream Symbol Rate : 2560 Ksym/sec
Upstream transmit Power Level : 37.0 dBmV
Upstream Mini-Slot Size : 2



So at 01:00 I'm only getting 5.66 Mb/s on the basis of speedtest.net @ Birmingham (and I'm not bothered). So on this occasion we can't pin it down to your high receive power level - but it needs attenuating anyway.

There's work going on in the network. That much is now clear and that's affecting us both.

Oh - and about that proxy server - you surely aren't gonna continue with that AV method?

But have to for the web scanner to work.

If I am receiving ok speeds why fix if it ain't broke?

I already had to have an attenuator fitted for the TV cable earlier funny enough.

India told me last night that the level wasn't anything to worry about, you believe that?

---------- Post added at 11:13 ---------- Previous post was at 10:58 ----------

Here are my speeds this morning with the same power level minus the proxy.

[Sephiroth]

You've had my advice in post #16 which is generally what better brainios than me say on this forum.

You need an attenuator IMO but I don't think this was your problem in this instance given the general network malaise.

[VMboy]

Originally Posted by Sephiroth

You've had my advice in post #16 which is generally what better brainios than me say on this forum.

You need an attenuator IMO but I don't think this was your problem in this instance given the general network malaise.

Ok, but please tell me what difference fitting an attenuator will do, if none then why bother?

[Sephiroth]

Originally Posted by VMboy

Ok, but please tell me what difference fitting an attenuator will do, if none then why bother?

The forward path attenuator will reduce the power entering the cable modem and hence any instability that might arise.

On the if it ain't broke don't fix it basis, you can choose when to report the matter to VM. In any case I'd wait until the current fuss is solved.

FYI up to a fortnight ago, my modem was always showing 29.6 dBmv upstream power. Had I posted that vealue here, I'd have got a "way too low" response. Yet my service has been stable. Now it shows 37.6 dBmv and I've done nothing on my side of the wall box. VM has done something to my circuit or the damp weather has required greater output power.

So you can see where I'm coming from and I do respect the "ain't broke" approach. Just keep your eye on it.

[VMboy]

Thanks Mate.

---------- Post added at 13:22 ---------- Previous post was at 12:43 ----------

I am getting these speeds, so nothing much wrong having that power level.

Download Speed: 10023 kbps (1252.9 KB/sec ) Upload Speed: 483 kbps (60.4 KB/sec )

[VMboy]

Can I ask if anyone knows why I get conflicting speed test results by using both the London and Sittingbourne servers.

They apparently are similar in distance, so I can only think it's due to utilisation perhaps.

The result below is London as you can see.



And this is the other from Sittingbourne

Because online speed tests are crap!

[VMboy]

Originally Posted by xocemp

Because online speed tests are crap!

Then please suggest a better and more accurate alternative.

ftp://ftp.virginmedia.com/blueyonder...h/ifhsetup.exe

Hosted by VM, save that and note the transfer speed.

[VMboy]

Crap transfer speeds.

I am certainly thinking of switching companies, Virgin Media are a complete and utter joke!

[Sephiroth]

Originally Posted by VMboy

Crap transfer speeds.

I am certainly thinking of switching companies, Virgin Media are a complete and utter joke!

But just one hour earlier in http://www.cableforum.co.uk/board/12...tch-to-vm.html you were saying that VM were much better than BT Openreach.

So if VM are a complete and utter joke, how would you characterise BT Openreach and why?

[darren.b]

Originally Posted by VMboy

Crap transfer speeds.

I am certainly thinking of switching companies, Virgin Media are a complete and utter joke!

I am sure VM have heard all these idle threats before. Pffft.

They aren't too far from you, why not go in there and punch them all in the nose? That'll tell 'em.

Actually, if I decided to go to BeeTee i would suffer a slower leech speed than I'd get on VM while throttled. Real fibre is nowhere near Edinburgh yet. So it's pretend fibre from United Artists/Telewest/ntl:telewest/Virgin Media or copper/aluminium/string from BeeTee.

Maybe if you paid an extra fiver a month and got "L" they might shunt you onto the newer kit (which has its problems too but at least you could leech faster)