annex M upload speeds

With Annex M it takes some of your download speed to give you faster upload speeds due to the frequencies it uses.
If you have not got full speed downloads due to distance or something else will you keep the same download speeds as well as getting faster upload speed or is it still a trade off ?

It operates the same way however it's irrelevant here. Enta don't do Annex M. Only some of the LLU operators do.

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Partly as ukfsn says, and partly the opposite of what you were asking.

It is only when very close to the exchange and getting in effect the top download speed on Annex A, with plenty of spare space in the frequency bins as well, that you can get the Annex M upload increase and still get the full download.

If your download on Annex A is limited by distance, which for most it is, then there is no spare space in the high frequency bins to be used instead of the low frequencies that the Annex M upload nicks. So a download loss is inevitable.

It is also the case that if the download connection speed on Annex A is below 15-16Mbps there is a high chance that Annex M will lower that even more, and you still won't get over 1.4Mbps upload due to the upstream attenuation also being high.

Tweaking apart of course, in all of the above. The effect of tweaking the downstream sync-time noise margin is to allow more speed at each frequency. At least one LLU company where support will lower the downstream to 3dB also lower the upstream. That is good.

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