No. Latency is how long a packet takes to travel.
The latency can be higher if distance to exchange is longer but on a bit of fibre latency will be negligible over a couple miles.

Latency on the link between cabinet and exchange has NO impact on the VDSL2 link speed, since it is not VDSL2 between the exchange and cabinet.

If someone can find the distances between exchange and cabinet that the ANFP uses to specific mask for a cabinet can do some analysis on speed test results to see how different or not the upload figures are.

In reply to a post by ironman12345:

But that is saying that no time is taken for the signal to travel to the exchange,?

No, it's not.

The sync speed is the number of bits per second transferred between the VDSL DSLAM in the cabinet, and the VDSL modem at the end user side. It's an attribute of this copper point-to-point link only.

Even if the fibre from the cabinet was cut, it would not affect the sync speed - it's just that data wouldn't be able to travel any further than the cabinet.

In reply to a post by ironman12345:

Surely if the cab is further from the exchange it must effect the speed.?

It does not affect the speed of the link between the cabinet and the user's VDSL modem, which is what we're talking about here.

For end-to-end data transfers over the Internet, there *is* a relationship between latency, maximum achievable throughput, TCP window size and packet loss. You can achieve any throughput you like, for a given latency, as long as the TCP window size is large enough and the packet loss is low enough.

In reply to a post by ironman12345:

Ok latency is the wrong word but as everything takes time, then due to power drops at further distances the speed would still be lower.?

There is no VDSL "power" sent along the fibre link between exchange and cabinet. The cabinet has its own mains connection, and the VDSL electrical signal originates at the cabinet.

So for VDSL sync speed, the distance between cabinet and end user matters (i.e. the length of the copper link); the fibre between exchange and cabinet does not.

My cabinet is at least 4.5km from the exchange and I have never had less than full 20Mbps upstream sync. This is the first time I have heard it suggested that distance from the exchange affects VDSL.

In reply to a post by candlerb:

So for VDSL sync speed, the distance between cabinet and end user matters (i.e. the length of the copper link); the fibre between exchange and cabinet does not.

But of course, I agree with what was said before: cabinets which are further from the exchange may be configured to use lower VDSL power in order not to interfere with ADSL, which in turn means for a given length of copper you'll get a lower sync speed.

I don't recall the question ever being asked before, Kevin . But the upstream power masking on the local loop theory makes sense to me.

Thank you for all the replies. Did BT Openreach decide the tone assignments and have they published anything to justify the decision that they made? Is it at issue that Ofcom gets involved with?

You can enjoy reading the ANFP NICC documents if you want