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[jid]

Hi Kitz and All,

Well, I decided to take a risk and get a new router!

D Link DSL-2740B

Well delivered today and it first synced at 6540kbps!!! However as I was setting it up I have had to reboot it a few times to get it all done and dusted, which I now have, I have also managed to get both DMT v8 and RouterStats to be able to work with it!

I have started to monitor with DMT, so I am monitoring SNR over a 2hour period(just started), screenshot:-


It all seems pretty good to me! At least the SNR ain't in negative figures

One thing I don't like though is the Interleave Depth, I believe its the highest possible?

So thanks to everyone on the forums for all of your help over that past few months, its greatly appreciated!

I will keep my eye on it over the next week or so and then maybe get the Target SNR adjusted and Interleave removed (condition depending).

Kind Regards

Jamie

[kitz]

Hi jid

I was just quickly looking at the forums before doing something else....  and I havent really had chance to look at your stats on there properly.
The graphs look very pretty...  but the immediate thing that strikes me... what the heck is that gap at around 862 kHz?
Dont have time to look up now but anyone know what transmits at around that frequency and why theres no signal.
That certainly doesnt look like any sort of ISP dslam block - look how it curves down and then back up again...  Noise???

[jid]

H Kitz,

Thanks for the reply.

On every refresh I do on the DMT, that gap is always there in the same place

Regards

Jamie

[Oranged]

JID :

Do you live near a hospital or electronics factory ?

I think 862 is in the ultrasound range......megasonic frequency ?

[jid]

JID :

Do you live near a hospital or electronics factory ?

I think 862 is in the ultrasound range......megasonic frequency ?

Nope, not that I can think of? Nearest to me is a Church!

[jid]

Here is the latest from RouterStats over 1 hour:-


I tell you what is great! I don't have to press enter twice to load a webpage anymore!!!

I am going to leave it well alone now to let it find its own stable rates etc. Hopefully I can return to normal with much more stable SNR

[jid]

Hi all,

Just looking at the stats this morning its now at 15dB!

Its been up for over ten hours so snr must have just floated up to that!

In light of the improved SNR do you think I could ask Tiscali to drop me down to a 9dB profile?

Cheers

Jamie

[kitz]

Just looking at the stats this morning its now at 15dB!
Its been up for over ten hours so snr must have just floated up to that!

Im not quite sure if you understand how SNR and SNR Margin works, but this is normal and happens on hundreds of thousands of lines in the UK.  SNRM does fluctuate.. its often at its worst in the evenings and better in the mornings.

Its why at one point why we were saying leave the router to settle to its own level... because if you boot up in the morning come the evening then SNRM will drop.. which causes your line to become unstable in the evenings.  If you boot up in the morning with a high speed.. it may be fine in the morning.. but in the evening it will all go to pot.

Some lines suffer more than others with SNRM and the amount of the fluctuation may be much higher.
The amount of this sluctuation could either be due to a line fault... or interference...  or its a long line which do suffer more.

Youre not on a long line, so you should get decent syncs.

• Have you got a screen cap of when the SNRM increased..  can you pin it down to a certain time?
• Can you post a DMT graph now - whilst the SNRM is higher.
• Hopefully theres not been a reboot as I'd also like to see your current stats.

As regards to that gap - its not normal and the indication is that somewhere you are picking up interference.

Ive had a google on those frquencies and its normal broadcasting channels.  Theres not a radio HAM that lives near you is there? Someone with a stonking big ariel in their back garden.

[jid]

H Kitz,

Sorry I don't have a graph of when the SNR went up as the PC or RouterStats wasn't on.

Mode :     G.DMT
Type:    Interleave
Line Coding :    Trellis On
Status :    Link Up 
 
                Downstream    Upstream
Rate (Kbps) :    6560     448
SNR Margin (dB) :    12.1     25.0
Attenuation (dB) :    30.0     15.5
Output Power (dBm) :    12.3     19.8
K (number of bytes in DMT frame) :    206     15
R (number of check bytes in RS code word) :    10     8
S (RS code word size in DMT frame) :    1     8
D (interleaver depth) :    32     2
Delay (msec) :    8     4
Super Frames :    1134510     1134460
Super Frame Errors :    238     0
RS Words :    77146710     9642910
RS Correctable Errors :    595162     0
RS Uncorrectable Errors :    364     N/A
HEC Errors :    163     0
OCD Errors :    0     0
LCD Errors :    0     0
Total Cells :    298397829     0 
Data Cells :    594129      0
Bit Errors :    0     0
Total ES :    66     0
Total SES :    0     0
Total UAS :    39     0

Connection Up: 5hours 30mins

This is RouterStats, since the time that graph started, the line is pretty much the same, no dips etc.


Here is the DMT, as you can see, gap is still there:-


No Amateur radio stations/broadcasts or big aerials nope

Cheers

Jamie

[kitz]

I was hoping that routerstats would have picked up the recording of the increase so you could see what time it happened and if it was gradual.. or if it was "flick of the switch".

That gap is strange and could well point to the root of your previous problems.. it could be that you actually have a REIN fault

[jid]

So that Gap is obviously some sort of high interference source then?

Its funny, as the SNR issues have now gone with the new Router? (Broadcom Chipset)

Its only been up 5 hours as I had to change the WiFi security settings a bit

I will leave it on now for the day and night and see the outcome in the morning, also router stats will run until I turn my PC off, and I will alert you of those results.

Say if it stays stable for the week, would it be worth removing interleave, or even dropping target SNR? Obviously 12dB SNR is holding the speed back a bit?

Thanks

Jamie

[kitz]

>> So that Gap is obviously some sort of high interference source then?

It would appear so - although this type of interference can also come from faulty monitors, or any other type of electrical equipment.

[jid]

>> So that Gap is obviously some sort of high interference source then?

It would appear so - although this type of interference can also come from faulty monitors, or any other type of electrical equipment.

Hmm, well the router is next to my monitor, if that makes a difference?

I won't do any moving around of the router yet as I want to leave it up for you to see the graphs etc tomorrow, however I may connect up to the Master Socket tomorrow and run DMT to see what it brings.

[Oranged]

I may be wrong but I believe some of the newer RFID systems run on a similar frequency.....tagging systems used in logistics warehouses....any large supermarkets or DIY or transport/logistics warehouses near you ?

Certainly ultrasonic cleaning systems use this frequency, but I didn't think it was used in this country by radio hams....USA yes.

From the graph it seems to run from around 870kHZ to 897kHZ then another smaller gap 900kHZ to 915kHZ.....strange.

[jid]

I may be wrong but I believe some of the newer RFID systems run on a similar frequency.....tagging systems used in logistics warehouses....any large supermarkets or DIY or transport/logistics warehouses near you ?

Certainly ultrasonic cleaning systems use this frequency, but I didn't think it was used in this country by radio hams....USA yes.

From the graph it seems to run from around 870kHZ to 897kHZ then another smaller gap 900kHZ to 915kHZ.....strange.

Well there is big ASDA next to my exchange if that makes a difference? Nothing near my house though!