SNR graph

Hello all,
My vdsl had been rock solid 80/20 until before Christmas but I new connection close to me seems to have lowered my max attainable speed. The graph on mydslwebstats shows lots of downward spikes, I have looked at other peoples stats and none look like mine, does anyone know what it means?
Peter

Do you keep turning the computer off that is running DSLStats? Or closing DSLStats? That would explain the lack of continuity in your SNRM graph.

Re the Max Attainable, which seems basically unchanged since you appear to have set up MDWS a few days ago, the new connection close to you could well have caused that, although we can't see what it used to be of course. It is caused by cross-talk between the two lines. It can happen at any point between the cabinet and you, and even be caused by connections far further on if their line between them and the cabinet is close to yours near the cabinet end.

Many people have seen theirs fall dramatically over time, and those not on full sync like yours have seen their actual sync fall as well. Sometimes by over 10Mbps. Were you one of the first on your cabinet?

Given what your Attainable is now, a re-sync would almost certainly cause a lower actual as well.

See mine: HappyBunny.

Edited by RobertoS (Wed 07-Feb-18 12:49:50)

In reply to a post by RobertoS:

Many people have seen theirs fall dramatically over time, and those not on full sync like yours have seen their actual sync fall as well. Sometimes by over 10Mbps. Were you one of the first on your cabinet?

And can be way worse! One line I have visibility of can have achievable of just over 82 Mbps and sync at Max. However, when one particular neighbour, thee or four doors away, (around 100m) turns their modem on, the achievable and sync drop to around 64 or 65 Mbps. Other neighbours have very, very little effect - just one is horrendous.

Blimey, thank god I have vectoring on my line eh!

I think I was first on the cabinet but was using the supplied ECI modem that never synced more than about 54mbs.
I have the program on a laptop at the moment, I must change it to a computer that is on 24/7.

Edited by Peterdevon (Thu 08-Feb-18 13:17:38)

Yes, the ECI and HG612 modems are way behind later ones on FTTC sync. They were good stable beasts initially but technology has moved on.

So has Openreach DLM of course. I reckon those two modems are low by 3-4 Mbps, with the rest of your increase coming from DLM changes. Maybe some from improved wiring at home as well?

Some current one are behind as well having replaced my Billion 8800NL with a 8800NL R2. The R2 is synced some 5 Mbps lower on both downstream and upstream compared to the V1. It could be down to the cheaper Broadcom chipset the R2 uses not playing well with ECI street kit but I'm waiting to see what Billion have to say.

I'll probably hang onto it for when I get my line for work in a few month time which hopefully will be on the new Huawei cabinet that is just waiting to be commissioned.

In reply to a post by simon194:

It could be down to the cheaper Broadcom chipset the R2 uses not playing well with ECI street kit but I'm waiting to see what Billion have to say.

It's exactly that. The R1 has the excellent (best on my line by far) BCM63168 chipset.
The R2 has Broadcoms budget chipset, the BCM63381.

Heck .

I was so pleased with my R2. Now I shall have to look around!

In reply to a post by RobertoS:

Heck .

I was so pleased with my R2. Now I shall have to look around!

They are decent modems. I like Billion devices.
They just cheaped out on the BCM chipset on the R2.

A modem with a BCM63168 will likely sync a little higher.
A few Mb more was worth the cost for me as I was only getting 36Mb at the time. Is a few Mb more worth it to you?

My BCM63168 modem of choice is the Zyxel VMG1312-B10A as it has an additional noise filter fitted to it. I only recommend this to anyone using it on bridge mode though as it has IPV6 issues of used as a router. They pop up on EBay between £30-40 quite a lot.

I've got one of those Zyxels with an AAISP-tailored firmware. I have considered flashing a bog-standard version into it, but the main reason I bought the Billion was to get over the infuriating IPv6 problem of the Zyxel .

AAISP are now putting out the B I think, which apparently is OK on IPv6. But is that also the slower chipset?

I shall probably stay as I am, given my speed and that 40/10 would be perfectly adequate! It was a reactive rant of annoyance. One of these irrational obsessions about getting the best possible out of the line just for the sake of it.

I'm seeing attainables frequently in the mid-76Mbps range and 30 minutes ago saw 77008, which is 1200kbps up from now.

I tried a couple of weeks ago to get just over the 76 point but it doesn't work like that. What seems to happen, (it has done twice), is that over time the both noise margins creep up and around day 24 I get a re-boot for no apparent reason and the actuals go up. Not necessarily overnight.

The downstream up-creep started recently, I'm on day 17. The upstream had reached 6.2dB several days ago and is on 6.3dB most of the time now. It's a weird effect. But I think I must be at near-best, as the other times the downstream up-creep has started earlier.

AAISP are now issueing the VMG-1312-B10D which has the cheaper slower chipset but works ok on IPV6. The VMG-1312-B10A has the more expensive chipset which consists of 3 chips and a filter and gains better sync from tests seen on Kitz users which I think is the same chipset as the Billion 8800 NL R1 whereas the R2 is a single chipset device with cheaper, lower sync chipset.

Thanks Tim. Yes, the D.

Like I said though, I think I'll stay as I am for now. Rather a lot of money has flowed out over the last four months!

In reply to a post by j0hn83:

In reply to a post by simon194:

It could be down to the cheaper Broadcom chipset the R2 uses not playing well with ECI street kit but I'm waiting to see what Billion have to say.

It's exactly that. The R1 has the excellent (best on my line by far) BCM63168 chipset.
The R2 has Broadcoms budget chipset, the BCM63381.

It's basically what Billion's Tech Support came back to me with yesterday so time to source another R1 I thinks.

I might hang on to the R2 to see how it performs on my work line when I can get it installed in a few months time because hopefully that line will be on the new Huawei cab that's just awaiting commissioning.