[AusNOG] ADSL2+ line sync data

Paul Brooks pbrooks-ausnog at layer10.com.au
Sun Sep 15 18:26:10 EST 2013


On 14/09/2013 3:05 PM, John Edwards wrote:
>  On 13/09/2013 09:33, Paul Brooks wrote:
>> At worst it should fall back to ADSL2+ mode.
> This assumes that the solution can get the PTM/ATM fallback working right for older modems.
>
> Also note that vectoring is going to negate the ability to "fall back" because everyone will need vectoring-compatible CPE.

Not really - lines that fall back to ADSL2+ mode will only be using frequencies up to
2.2 MHz, and probably only up to about 1.5 MHz or so at those distances. The higher
VDSL2 frequencies used by other shorter lines aren't bothered by them.

Anyway, at least 2 vendors claim they can compensate for non-vectoring-compatible
VDSL2 CPE by varying channel maps and transmission powers at the DSLAM for those
lines, and achieve almost the same results.
I'd still really like to see it to confirm, but thats what the brochureware claims at
least.

P.



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