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[Weaver]

Apologies the A in ADSL just means asymmetric, which is the point of the article, so I should have written simply "DSL" to cover VDSL too (which arguably should have been called VADSL).

I don't know much about VDSL, but I'm afraid that it's equally true for VDSL2, that the split cannot be varied by the user or ISP.

[loonylion]

VDSL can operate in a symmetric mode, OR just choose not to offer that.

[Weaver]

I should have mentioned Annex M. I forgot Annex M altogether. If you have modems at both ends that speak Annex M, a chapter of the protocols, then the split frequency can be changed to one alternative position. The default means lower speed upstream and higher speed downstream. The split point is not arbitrary though, there are two choices only. So this is what you want, turning off Annex M increases the downstream speed, but then that's it, there are no further higher speed downstream possibilities.

I don't believe Annex M is available for VDSL2 so it's not available to you anyway, and as I said the setting regarded as the default is "higher downstream speed".

[roseway]

Sorry for necro, but given it's my thread and related, I wanted to ask: My line speed dropped since I posted the 1st post from 79999 to 69055 ... although it's still not to shabby, I'm not exactly a happy bunny.

Both the HomeHub 5 Tyeb B and the HG612 3B unlocked with latest f/w B030SP08 give the same speed. HG612 line stats below.

Anything I can do to bring the downstream speed up? Can one trade SNR margin from uplink to downlink (I recall something like this from old ADSL days about 13 years ago).

The drop in speed over time is most likely to be the result of crosstalk, and there's really nothing you can do by yourself to restore the loss. You already have G.Inp enabled on the downstream, and without this your speed would most probably be lower still. You're in "join the club" territory.

[alexw]

The drop in speed over time is most likely to be the result of crosstalk, and there's really nothing you can do by yourself to restore the loss. You already have G.Inp enabled on the downstream, and without this your speed would most probably be lower still. You're in "join the club" territory.

Darn it. Many thanks, though.

I'd like to understand this better. Surely the wiring from the cabinet is the same since 2013 when I was getting 79999 kbps, so do I take the extra crosstack comes from new wiring (customers) added to the cabinet or building (it's a block of many flats)?

[roseway]

Crosstalk is interfering signals leaking between different pairs of wires in the same cluster. For interference to occur, the different pairs need to be carrying a similar range of frequencies. When the first users are set up on a new FTTC cabinet, there won't be many interfering pairs because only a few carry FTTC signals. But as more users are added the level of interference increases and speeds are forced down.