Concerned about Router stats and constant line drops

Hello!

I've recently been experiencing constant disconnects due to my SNR dipping below 6db, this usually only happening at night.

I remedied this by requesting a 12db SNR target, so when these dips happen, I'm not going below six, hence keeping my line stable, of course this has come at the price of a lower sync speed.

with the 12db target the line still fluctuates quite abit, dipping as low as 7db for a moment then jumping back up, leading me to think there may be a problem on the line or in the area

Samknows says I'm 1.7Km from the exchange and I'm getting a 45db downstream attenuation, which equates too about ~3.5Km calculated magic length.

I've just ordered a Billion Router to be able to play with the Tx Attenuation and other tweaks.

What do you guys think?

Thanks.

I think you're looking in the wrong place. Sounds like you have line noise problems.

I've done the quiet line test on the 17070 number and I cant hear anything, no crackle or pops at all.

That's good news.

Try plugging the router in the test socket behind the master if you have one. See how that gets on.

I've replaced my Master with the ADSLNation one, and the box in my office with the integrated splitter faceplate, no other phones plugged in else where in the house.

Orange (ring) wire disconnected at master, and only the pair needed is wired in.

Tried it in the test socket, shows no difference what so ever and the disconnects are still present there, so my house wiring is pretty solid I reckon.

So what story is Routerstats telling? What's happening with the SNR Margin?

noise margin downstream: 12 db
output power upstream: 12 db
attenuation downstream: 45 db

noise margin downstream: 9 db
output power upstream: 12 db
attenuation downstream: 45 db

noise margin downstream: 7 db
output power upstream: 12 db
attenuation downstream: 45 db

noise margin downstream: 11 db
output power upstream: 12 db
attenuation downstream: 45 db

I took those within a couple of seconds of each other, the line is stable with the 12db target since its not dipping too low.

but with the 6db target, it was dipping as low as 1-2dB and then loosing sync, it'd do this every couple of minutes too.

--- here's also a full capture of ADSL line logs.


DSL Line Status:
noise margin upstream: 11 db
output power downstream: 19 db
attenuation upstream: 29 db
tone 0- 31: 00 00 00 06 78 9a bb bb bc bc bc bb bb bb aa 90
tone 32- 63: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 64- 95: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 96-127: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 128-159: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 160-191: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 192-223: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 224-255: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 256-287: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 288-319: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 320-351: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 352-383: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 384-415: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 416-447: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 448-479: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 480-511: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
noise margin downstream: 11 db
output power upstream: 12 db
attenuation downstream: 45 db
tone 0- 31: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 32- 63: ab bb cc cc cc bb bb 9b bb bb bb bb bb bb aa aa
tone 64- 95: 0a aa aa aa aa aa aa aa aa aa a9 9a 99 99 99 99
tone 96-127: 99 99 99 99 99 99 99 99 99 98 99 89 98 88 88 88
tone 128-159: 88 88 88 88 88 88 78 88 78 88 88 88 88 88 77 87
tone 160-191: 75 77 77 77 77 76 77 76 77 77 77 77 67 56 07 66
tone 192-223: 66 06 66 55 04 00 44 56 65 50 44 50 42 00 00 00
tone 224-255: 20 03 40 04 24 44 05 45 45 44 03 04 44 43 20 00
tone 256-287: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 288-319: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 320-351: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 352-383: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 384-415: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 416-447: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 448-479: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
tone 480-511: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00

DHCP: N/A

ZyNOS Firmware Version: V3.40(AZB.3) | 05/19/2009

WAN Information:
DSL Mode: ADSL_G.dmt
IP Address: 95.172.236.160
IP Subnet Mask: 255.255.255.255
Default Gateway: N/A
VPI/VCI: 0/38

LAN Information:
IP Address: 212.105.164.121
IP Subnet Mask: 255.255.255.248

What does Uno say?

Uno / Xilo have said its most likely a problem with BT, and it'd be an engineer call, not really too keen on that considering there may be a price-tag attached so wondering if there anything else I can investigate / try.

yes, I'd tend to agree. Looks like you've ruled out your wiring although I'm a little concerned that the stats don't change at all when you're in the test socket.

A different router will rule the router out too.

I thought you were already running Routerstats, so I'd suggest running that to get a graphical view of what's causing the problems - http://www.vwlowen.co.uk/internet/files.htm

I'm just giving routerstats-lite a go now, polling ever 5 seconds, sharp jumps from 10 to 7 constantly. I'll post an image once its ran some time

I have a Billion 7402 coming tomorrow hopefully so It'll be interesting to see what stats that produces. as for the test socket not making any difference on the drop outs and snr fluctuations it comes as no surprise as I only have 2 phones on the line, and they're well filtered.

Let routerstats run allnight and day, there's no moment where it actually sits still, it jumps from 12db to 8db constantly, sometimes it goes down to 7.

There was 3 cases where it dropped stright down to 4db, but 3 times in a 24hr period doesnt bother me that much. The billion hasn't come so it looks like it might be next week before I get to try that out

Sounds like you're getting a lot of RFI or other electrical interference from somewhere. Have you got the router sitting on top of a PC or by the monitor?
Maybe the power brick for the router is failing?
Are all the phones filtered?
Have you got a skybox or something?

I might have missed it but I don't think you've said what router you are currently using?

Going by the firmware you mention (ZyNOS) it looks like it might be zyxel ?

It looks like these might use the TI AR7 chipset - this was dead loss (in a Netgear DG834v2) on my line with terrible SNR management.

I tried a few routers (see my RouterStats Graphs) and transformed things with a Thomson 585v6 (broadcom).

I think Billion use broadcom so it will be interesting to see if it can help your line

It is a Zyxel 660HWP-D1 which apparently is notorious for not handling SNR's below 6dB very well, probably based on the chipset. I just checked the router gubbins and sure as damn it, its running the TI AR7 07.02.03.00 chipset.

My Routerstats graph is very similar to the graph for the Netgear, very spikey and between 12 and 7db.

The Billion 7402R2 uses a Conexant chipset as far as I'm aware, but does come with features to tweak the SNR like other broadcoms. I'm going to try this Billions since I picked it up for 15 quid, so even if it doesnt make it any better, I'm not at much loss

I'm a radio amateur so I'm very RFI concious, I've made sure the extension to the office doesn't have many staight long runs and clipped on some RF Chokes as well.

The only thing in the house that could possibly cause the problems is the dimmer switch in the adjacent room, but with it on or off seems to make no impact on the SNR.

As I mentioned previous (I think) all the phones are on ADSLnation filtered faceplates

So what frequency is the noise coming in on?

Argon 330 (7402), Argon 432 (7402R2)
The original 7402 was produced with a GlobespanVirata chipset. Later production incorporated the Argon 330 chipset, a GlobespanVirata legacy product from Conexant. The 7402R2 incorporates the newer Argon 432 chipset, bringing it into line with the rest of the 74xx family.

The above can be found here, about two thirds of the way down the page

That's anyones guess, could be interference coming in on the line before it even gets into the house, you never know!

I've not yet ruled out that the noise could be on the extension line that comes up the house and through the loft although there is the chokes on it, I'll have to do a run with router stats with it in the master socket and see if theres any difference.

If its that, its not too hard to just replace the poxy phone wire with STP or FTP cable.

Just did a run with routerstats plugged in at the master socket, no difference what so ever.

In reply to a post by SamuelJones:

That's anyones guess, could be interference coming in on the line before it even gets into the house, you never know!

Well don't guess, tune in a MW radio and see if you can hear it.

Where you say 'master socket' are you using the 'BT Test Socket' behind the removable faceplate? - just checking.

Shame your new router isn't based on a Broadcom chipset. If you can get your hands on a 585v6 or DG834GT (or similar broadcom based router) it would definitely be worth a try to compare things. Hopefully you'll find it was the AR7 chipset that's causing your issues like I did.

Billion 7402R2 arrived today, set the Tx Attenuation to 4db (I get a good upstream SNR) and its improved no end of things, as well as the chipset being more stable

Still on the 12db target, but the billion is hovering at 16db, with a line attenuation of 43db as opposed to 45-46db.

Just requested a SNR reset on my line, but with it being saturday I dont think Xilo support are in the office to do it

You may want to check your ticket - was replied to in just over an hour for you

Matt

Can't beat Xilo/Uno tech support, even on a saturday!

I've just done a quiet-line test with the new router, and I've noticed something odd, which may have to do with the problem..

I can hear the ADSL on the phone line, when I disconnect the modem, the noise goes. when you reconnect the modem, you can hear it do the handshake and then eventually making a racket.

its very quiet though, you almost wouldn't notice it if you just listened to the dial tone.

I'm presuming this isn't normal and could factor into my attenuation? though I think this issue might be only one way, I'm hearing my modem, but not the dslam, so only effecting my upload? this is my un-educated guess!

Still waiting on the SNR reset too, its been provisioned but its been the weekend so its too be expected

http://scjones.co.uk/graphs/Billion_Router_11.html theres my live line stats much more stable now, will be interesting to see what my sync jumps too when the 6db target is on.

Don't worry about the noise on the line issue! I fixed that!

Apparently in the line profiles section of the Billion settings setting it to BT makes this noise come... so its obviously not as BT friendly as I thought, once set to MAIN (the default) the noise went away!

Interleaving has just been switched off and the lines holding steady at 12db SNR, so fingers crossed it'll all be rock steady on the 6db target!