Those stats for sync and noise margin are really good. So what happens when the Homehub is switched on? The noise margin plummets? The throughput dies?

Thanks for the info, good to know it should work ok.

Couple of questions, are both you lines in the same drop wire or 2 separate drop wires?

Which OR modems, HG612 or ECI

I've ordered 2 modems for tomorrow but don't mind investing in a couple of OR ones to try as well, just want to get it sorted, lost almost a whole day today baby sitting the BTOR engineer.

Yes, before todays *fix* the TT modem would still sync at 78M and show a max rate of 79M, so circa 20M was lost from the max rate but no real impact on sync. SNR dropped to 6dB.

Now if I switch on the BT HH5, the TT sync drops to about 56M 6dB SNR and max about the same, so 40+M lost from the max rate.

Also if I switch on the BT HH now the initial effect as it syncs is a complete TT disconnect, SNR goes to 0 and even negative followed shortly after by a resync to the slower speed.

The BTOR test kit also had the same effect so I can't blame it on the HH5, however when we simulated a second drop wire hanging off the pole the sync still dropped but to 75M not 56M, still worse than when he started though.

Somehow he seems to have increased the high frequency coupling/crosstalk between the 2 pairs but says he done nothing except re-terminate some joints on the BT line between the house and the cabinet.

He's probably got a blob of solder bridging a gap or something. Definitely another fix required.

I think they only use horrible crimps

In reply to a post by woodpeckerx:

DLM doesn't seem to be on either line as both will sync on their own to 79987.

DLM can intervene on a line, and it can still result in a sync speed of ~80000. For that to happen, the pre-intervention maximum speed would probably have to be around 88Mbps or more.

In reply to a post by woodpeckerx:

Another thought on DLM, for a few weeks the BT modem was reporting 57M sync but 69M max line rate, shouldn't DLM have raised the sync to nearer the max?

If DLM has intervened, then the actual speed will always be less than the maximum.

A quirk in the algorithm (of the HG612 modem) that estimates the maximum means that it over-estimates the maximum value when DLM has intervened. Perhaps your equipment does the same... If so, then when DLM removes the intervention in the case you give, the sync speed is likely to increase to around 63Mbps, while the max would drop to around 63Mbps.

My line (on an HG612) synced at around 78Mbps just prior to DLM intervention, and a matching maximum. It now comes up with an actual speed of about 72Mbps but the maximum increased to 84Mbps.

I see what you mean, repeated throughput tests on a wired connection are only giving 55M on the TT line which says it synced at 79987. Throughput before was always well over 70M, I wonder if the sync rate shown is even correct?

Maybe DLM is limiting throughput after todays playing? Its a right old mess now, wish I'd left it alone but BT said it must be a fault so decided to send out BTOR.

Hi,
I had my two lines (same drop-wire) upgrade to Zen Fibre two weeks ago, both lines sync at 79999 19999 and both have a throughput of 74 Mbps using two Openreach HG612's (Huawei Cab) connected to a Draytek Vigor2925n+ dual wan router

I am very pleased with the performance as prior to Fibre I had 2 Meg on one line and 2.8 on the other!

Paul.

This is typical of crosstalk in my experience. Especially if the distance to the cabinet is only a little more than good enough for 80mbit/s .

I get the exact same thing with 2 neighbours 1 on the same phone pole. if the one on the same pole turn of their modem, my speed goes up to 74-80Mbps, from 56mbps, another further up the street if their's is off to I get 80Mbps with a 8-9db noise margin.

If your lucky enough to have 2 80Mbps line you must be pretty close to the cab, or have 2 lines in different cable clusters.

I dont know why people are going on about DLM.

I dont think your lines are interleaved, to the point the FEE is wiping out 40mbit.

They definitely not banded as banding doesnt affect attainable rate.

Looks like a clear case of crosstalk to me.

Now normally openreach will say "tough luck" on crosstalk but because you own both lines and can prove it to a visiting engineer I guess is why they trying to fix it.

Edited by Chrysalis (Sat 23-Aug-14 07:05:08)