BT Openreach master socket

[DIYspanner]

The upper socket is for the Fibre optic modem and lower socket is for the telephone.

If you change from fibre down to ADSL broadband, does the DSL lead from the ADSL router plug into the Fibre optic socket?

 

[plugwash]

The upper socket is for the Fibre optic modem

Nitpick but PLEASE don't call it a "fiber optic modem", it's a VDSL modem. It's a travesty that the advertising standards agency lets communication providers get away with advertising fiber to the cabinet services as "fiber optic" but please lets not add to the confusion by reffering to devices as things they clearly are not.

If you change from fibre down to ADSL broadband, does the DSL lead from the ADSL router plug into the Fibre optic socket?

Yeah the filter BT install for their FTTC+VDSL service will work just fine for ADSL.Top socket is unfiltered for your DSL modem or router with built in DSL modem (as is the norm for ADSL in the UK), bottom socket is filered for phones.

 

[DIYspanner]

Thanks for the reply posting plugwash and the informative content.

You'll have to forgive my ignorance for calling a VDSL modem a fiber optic modem. I was using the term fiber optic modem because that's what Talktalk, my ISP uses.


I'm trying to sort out a downgrade from fibre to ADSL for someone who doesn't need the speed (they're close to the exchange) and don't want the extra expense. Talk had originally quoted 24 hours for the switch to be completed but its over a week and still not done.

 

[plugwash]

I always got the impression that talktalk were at the cheap and nasty end of ISPs.

AIUI moving between FTTC service and conventional DSL service requires physical rewiring by openreach both at the telephone exchange and at the cabinet so it doesn't surprise me it takes a while to arrange.

 

[DIYspanner]

So with the BT grid, the fibre optic cabling runs as far as the local fibre optic cabinet, then its copper wire for the rest of the run up to the master socket in the house?

In this case the only impedance to speed on fibre optic broadband is the run between the cabinet and the house which could be considerable.



I've noticed that the ISPs offer 38mbps and 76mbps speeds.

Is this determined by the distance of the cabinet to the house?

 

[plugwash]

So with the BT grid, the fibre optic cabling runs as far as the local fibre optic cabinet, then its copper wire for the rest of the run up to the master socket in the house?

Right.

Normally in the UK your phone line the phone line from your house goes to a distribution point (in areas that use poles this will be a box up the pole, there are also underground equivilents), from there it goes to a primary connection point (usually a green cabinet at the roadside) and from there to the telephone exchange.

With fiber to the cabinet the phone line is diverted at the primary connection point to a nearby fiber cabinet where it connects to a VDSL DSLAM. The phone line returns to the primary connection point and then goes to the telephone exchange as normal. The data service to the telephone exchange on fiber.

I've noticed that the ISPs offer 38mbps and 76mbps speeds.

Is this determined by the distance of the cabinet to the house?

Note that both of those are "up to" speeds, actual speeds will depend on the line from cabinet to house.

You can certainly order the 38Mbps speed on a line that is capable of supporting more. I'm not sure if they do any additional line checks to stop people paying for the higher speed when they can't take advantage of it.

 

[DIYspanner]

Thanks plugwash

I've decided to have fibreoptic installed - 38mbps.

Talk did a test when I was on the phone with their tech dept. and they claimed that at best I'd get about 48mbps, hence I opted for 38mbps.

The newly installed fibreoptic cabinet is about 400m (google maps) in a straight line, away from my house.

 

[SimonH2]

The 40 vs 80 is part technical, part marketing. IIRC the original FTTC was "only" 40Mbps, and after a while they doubled it as technology improved and/or got cheaper. If you are on a long line, they might only sell you a 40M service, but other than that there are typically marketing differences - for example my ISP offers unlimited data on the 80M service, but not on the 40M service.

 

[Lectrician]

Had my 80M installed yesterday. Green cab approx 100m away. I achieve 78-82M on speedtest.net on Ethernet PCs.

I have two wifi APs, and both only allow me to get up to 30M on laptops and iPads. That's with 802.11n, with AP set to N only, and little or no distance. Need to do some research and testing...

 

[SimonH2]

That's common, a lot of the cheap routers sent out by the cheaper ISPs only do "G" which can't match the FTTC speed at all. Are you 2.4G only or do you have dual band 2.4/5.8G ? The later will give you better speeds if your devices support it.

 

[Lectrician]

No, mine are both N, not G. Single band though.

They are not ISP supplied either, ones a business grade Draytek, and the other an outdoor EnGenius branded one. I also tried a spare Netgear I have. All gave similar results.

If you set your AP to N only (so not backward compatible with G or B), it is meant to sync at a higher speed. If you select B, G, N, they often sync to the G speed on N devices. If you have dual band, it keeps B, G on one frequency, and the N on the other, allowing the N to work faster. As I have mine set to N only, having dual band should not make any difference, although I believe you can use a fancy wireless card that uses both frequencies at once to give greater throughput?

 

[plugwash]

More importantly if both your router and your device are dual band you get to use the 5GHz band which tends to be much cleaner than the 2.4GHz band (both because it's less widely supported and because it has shorter range).