In reply to a post by MHC:

So far, the comms room has a "max attainable of over 100Mbps ... one install used in the Project Manager's office is seeing around 50-60Mbps - probably due to noise. Run 30 more connections and there could be serious issues on some.

Sounds like a catastrophe unfolding, with lots of very displeased occupants. "Pants" might be the word they use when being ultra-polite.

Most the crosstalk issues will occure at the DP and in the main drop back to the PCP/OR Network...

It's pretty certain that that attaiable wil drop very sharply as more connections go online and in the comms room or not will eventually probably end up as low as 60meg perhaps... I know I went from 116/32 to 79/25 as flats have come online... out of 24 flats I think theres still around 5 to go on yet... and a fair few have opted for ADSL instead of VDSL...

Talking of ADSL, how are you going to combat that?

Have you considered using sheilded cat6 for longer runs or even all runs, it may help a little bit?

Crosstalk in apartments is always bad.

It was noticeable for me way back when on ADSL 2+. Very few had ADSL 2+, it was a very new thing only available from a couple of suppliers so I could see the crosstalk up to 1.1MHz then disappear after that point.

Usually you start off on a line with high bit loading at lower frequencies due to lower attenuation however on that line I had the best bit loading by a mile at >1.1MHz.

I got my revenge by running over-powered, non-masked Annex M so it was all good.

In reply to a post by MHC:

The owners of the apartments will not have a choice - BT only for the infrastructure and then free to choose whichever ISP they want. Similarly - they cannot have their own Sky TV dishes or terrestrial TV aerial - these are managed and served to each apartment. And Virgin Media is ruled out as they will want to run coax to each apartment and the building management say NO.

I was referring to mass-market ISPs troubleshooting with customers who don't have a master socket terminating in their apartment.

In reply to a post by Ignitionnet:

Crosstalk in apartments is always bad.

I assume this is because of the meeting at DP's (lots of exposed cabling in one place)

In reply to a post by mlmclaren:

I assume this is because of the meeting at DP's (lots of exposed cabling in one place)

The DPs carry many more lines than DPs serving houses.

All I am doing is helping sort out the cabling that is going in and ensuring it is flexible enough to support many options. The possibility of putting the modems in the comms room was considered - yes it causes some issues and sorts out others ... and BT OR agreed it could be done. In the end, do they want to have to keep sending someone out, even if chargeable, because of a "slow" connection? Probably not.

The cabling will be there, BTs agreement will be there, the customer can then decide what he wants to do.

The cabinet is close by and currently has a good number of connections so there is already a high level of crosstalk (I would guess) it is te potential for high levels of noise in the building, some of which is already seen, that is the concern.

The builder (not the developer) is also trying to be awkward on the cabling side and, metaphorically, his head is to be banged against a wall!

The DPs carry many more lines than DPs serving houses.

That is a rash generalisation I'd say.

Crosstalk doesn't just happen at the DP itself, it is present throughout the cable run.

The UG DP in the underground box outside my house serves 12 properties, but also running through there are the feeds to a further three more DP's so the affects of all those properties lines are present in the cable feeding my DP. Drop back over the road where the feed cable is 100 pairs, here it splits to send 50 on to my DP and those beyond it and the other 50 go to feed the maisonettes and houses on the other side. So the 100 pair has many working lines in it, my pair passes through all these, how is that any different to a 100 pair DP in a block of flats ?