Annex M

Does anyone do Annex-M any more?
I checked with Zen yesterday and apparently they've stopped doing it

We can still do Annex M

Loads that still do.

AAISP, IDNet, Talk Talk Business and Plusnet to name a few.

Matt

Annex M is not available on Plusnet residential accounts.

The thing is, Annex-M has become an anachronism in most locations. It was only ever worth it on shorter lines -- the very lines that now get far better performance with FTTC/VDSL.

The problem is that the upper half of the frequency band for the Annex-M uplink is used for downlink on everyone else's lines. So crosstalk is a huge problem on longer lines. While bins 7-31 and 64-96 perform strongly, bins 32-63 can support surprisingly few bits, due to crosstalk.

I'm on a 3 km line, where FTTC won't do much for me. I migrated from Plusnet 20CN (Pro) to Pulse8 a couple of months back and have been struggling with this very issue (wholesale TalkTalk Business). To its credit, Pulse8 actually volunteered to downgrade me to Annex-A, because I wasn't getting value for money. I've not taken them up on the offer (yet), but I estimate I'll lose ~300 Kbps up, but gain ~1500 Kbps down.

Wasn't thinking straight when I wrote 1,500 Kb/s -- I meant 1,000 Kb/s.

And after the downgrade, I've gone from 12.1/1.3 to 13.0/1.0 -- on a 3 km line with 38 dB attenuation, I don't think I'm going to get much better with FTTC, do you?

How far away is your cabinet from you? FTTC is dependent on cabinet distance rather than exchange. My cab is around 600m away (by actual cable run) and I get about 45Mb/s on FTTC. Do you know where your cab is?

Heh, yeah forgot to mention that my cab is right outside the exchange. So still 3 km (length confirmed by an SFI engineer, BTW).