Will I lose speed when switching FTTC ISP to Zen?

Does anyone know if there's a strong possibility my ("FTTC") connection can/will be slower when I switch ISP from BT to Zen?

It's the only reason I haven't switched yet. I've already lost ~12Mbps since I signed up for BT Infinity two years ago so the last thing I want is to lose more.

I mean, theoretically it shouldn't since I'm connecting thru the same copper line/cabinet.. right?

Your speed drop is more than likely nothing to do with your ISP if it's happened gradually.

It is almost certainly a case of crosstalk around your line, created by more and more customers in your area taking up FTTC themselves. They interfere with each other slightly, causing speeds to drop. It won't subside until BT rolls our vectoring which should eliminate the crosstalk, but there's no timetable for that to happen. Many people have had much more serious drops in speed than the 12mbit drop you've seen.

I think wherever you go you'll find you'll get the same speed as the underlying connection will still be limited by the sync rate of your modem.

I am lucky enough to get the full 80/20 sync as I am very close to my cabinet (under 50 metres) but on my unlocked modem I have seen my attainable rate drop from almost 108mbit to 95mbit over the past 2 years. Obviously it has not affected me given sync is limited to 80/20, but the drop in what the modem thinks it can achieve going down is going to be due to crosstalk.

What does the BT checker estimate you should get on your line? (LINK)

Thanks for all that information. Really curious about this vectoring technology but I'm guessing by the time it's rolled out, I've probably moved onto FTTP/FTTH.

BT speedchecker: results.

Sync stats:

Text
1 23 45 67	# xdslcmd info xdslcmd: ADSL driver and PHY statusStatus: Showtime Retrain Reason: 0Last initialization procedure status:   0 Max:    Upstream rate = 25843 Kbps, Downstream rate = 66988 KbpsBearer: 0, Upstream rate = 20000 Kbps, Downstream rate = 67219 Kbps

Two years ago their speed checkers advertised a maximum of 57Mbps for my line which is about what I got when the line was installed but since I'm not that far from my cabinet I expected higher speeds so I asked the BT engineer. He made a call, and 10-15 minutes later I was getting around 74Mbps.

I'm under the impression that the cabinet's available throughput was somehow manually limited, that the engineer unlocked it and I'm worried when I switch over to Zen, I'll get the quoted maximum speed instead of the ~62Mbps I get now.

Oh well, I think I better call up Zen and ask. I just hope their sales team knows their stuff as well as you guys do.

Edited by deleted (Sat 12-Jul-14 13:03:10)

I'm not aware of any circumstances under which your cabinet would be artificially limiting you beyond the wholesale product of 40/10 or 80/20 limiting max speeds to their respective brackets. I can't think why that would ever happen. I'm not sure what that BT engineer could have done to 'boost' you up to 74mbit with a mere phonecall (perhaps he can make another? )

From your modem stats it looks pretty spot on to fit within the BT estimates. You're roughly in the middle of the range it gives for the 'clean' result. You modem also agrees you're basically getting as good as you're likely to get from the 'max' figures it's stating there too. It's doing the best it's able to given line conditions.

Your reduction in speed is almost certainly the result of crosstalk, and so I don't see that sync rate is going to change (in either direction, faster or slower) if you do or do not switch ISP.

On the face of it migration of FTTC shouldn't result in a drop in sync speeds

But some ISP's do select different DLM profiles which could result in you loosing some sync, as all 3 DLM profiles will have different error rate thresholds, Zen i believe choose the Speed or it's Openreach equivalent profile which is supposed to favour gamers, so in theory should have the highest error rate threshold so less likely for dlm to intervene, Where as i believe BTretail select either stable or standard options , The drop in speed is likely due to DLM only a dlm reset or switching to 40/10 and back will restart it so it syncs as fast as the line will support , but it could be short lived if the line is erroring bad enough

In reply to a post by tommy45:

Zen i believe choose the Speed ..., Where as i believe BTretail select either stable or standard options

This is nonsense. Do you have any proof or have you made it all up again?

The proof is on here or the zen forum, and was confirmed by an employee of zen, Plusnet also select the same as zen for FTTC orders
As for what BT retail choose as their default profile that too has been put out there, and it didn't comes as a suprise that they elected the standard or stable option, because thats typical of BT

Edited by tommy45 (Sat 12-Jul-14 20:10:01)

No, you're wrong. It was because BT Retail were opting for Speed that Zen realised their mistake.

BT Openreach Speed = BT Wholesale Standard
BT Openreach Standard = BT Wholesale Stable
BT Openreach Stable = BT Wholesale Super Stable

No the confusion was that Zen also provide a GEA FTTC product over their own network where they have a POP which doesn't use the BTwholesale mappings that's what caused the confusion from what i have read about it, And they will preumably order directly with openreach so they ordered with the openreach standard profile for a while until they realised , but now order using the speed option where they have their own backhaull
Sky is reported to select the Standard option which will be the openreach standard not bt wholesales , where as plusnet and zen(for orders via BTwholesale ) both use the bt wholesale standard =openreach speed option ,

Edited by tommy45 (Sat 12-Jul-14 20:22:54)

In reply to a post by tommy45:

from what i have read about it,

Oh, so you're not speaking from experience then? You're not on Zen Fibre or Infinity?