Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[kitz]

Just an observation thread on cross-talk disturbers which may (or may not) interest others.

Barring the work that BT did a few weeks ago which messed up my line, Ive sat quite comfortably at 8.1/8.2 dB for a while and the downstream  Downstream SNRm has/was quite steady.   Then last week I noticed an acute and sudden drop from 8.1 dB to 6.9dB and a loss of circa 5Mb from my max headline.  The downstream SNRm is also now subject to a bit more variance..  but what is interesting is I can literally tell each time the disturber does a reboot as my SNRm will momentarily spike back up to its previous 8.1/8.2.

What I find funny is that last night at 02:03 I suffered a very sudden burst of > 1,000 CRCs, my line held on..  but it looked like whatever caused my CRC spike may caused the other line to lose sync because at 02:04 my line briefly recorded back up to 8.2dB SNRm for 2 mins.   Then back down again as no doubt the disturber's line came back up.

[Chrysalis]

yeah your attainable not much over 80 now   I think the attainable is not over estimated at least circa 5mbit for .9db of snr seems reasonable?

right now my billion is estimating 76009 on a 72916 sync with a 6.6db snrm.

[guest]

Mmmm I think I've been there - if you remember how my snr collapsed from 18 or so (IIRC) to 7dB in the course of a couple of months. I occasionally see it increase by 1-2dB but not for long.

Anyway its still at 79987/20000 on whatever the minimum error correction setting is on Openreach VDSL2 kit (latency to these forums is 9ms) and has stayed up for over 6 months at 6.9-7.1dB. Lost IP connectivity (which triggers a resync on Sky routers, don't ask me why) last week for 5 minutes due to Sky having to (finally) sort out their DNS - believe it or not they didn't support TCP connections, which again shows why you should never use your (major) ISP's DNS but I digress.

I haven't seen any further degredation over the last 9 months. I guess that probably means Virgin have this area stitched up - I can live with that

Hope you're well etc, will have a catch-up with you via PM. /me spent part of the summer in an area where people were shooting at each other (and for once it wasn't the middle east )

[Chrysalis]

On my original pair I used to see lots of snrm jumps with some lasting for a few days, I guess a crosstalker who was disconnecting, but after openreach came to check a fault, all those snr jumps immediately stopped.

My original pair went down from 110 to eventually below 50 without interleaving, but as I dont know if the below 50 was a fault or not, prior to that it went down to around mid 60s.

[pooclah]

I’ve got a neighbour doing refurb work to his house so now and again his power goes off and this is what I see

[burakkucat]

Yes, that's a nice clean example of the syndrome. 

[konrado5]

It is similar to the SNR margin raisemens which I observe.

[burakkucat]

It is similar to the SNR margin raisemens which I observe.

So now all you need to do is to identify the precise cause of your observed "raisements" . . . In pooclah's case it is when a neighbour's CPE is powered down.

[konrado5]

Is it similar? I'm not sure. My graph is updated every second.

[burakkucat]

Is it similar? I'm not sure. My graph is updated every second.

No it's not. You do not have the same "block increase" coincident in DS & US.

Also Eric has explained to you that it is a nonsense to attempt to harvest data every second. What data you are collecting will not be valid as it takes longer than one second for the modem to respond to the request for the information.

[konrado5]

Also Eric has explained to you that it is a nonsense to attempt to harvest data every second. What data you are collecting will not be valid as it takes longer than one second for the modem to respond to the request for the information.

I see that I have no significant delay. AS (available seconds) data are second higher every second.