Annex M speeds and ISP?

I am trying to work out if I switch ISP what Annex M upload speed I would be getting based on my line stats. Currently on 21CN with a DG834PN

ADSL Link Downstream Upstream
Connection Speed 16571 kbps 1176 kbps
Line Attenuation 28.0 db 13.9 db
Noise Margin 5.2 db 6.0 db

I am not sure if it's even possible to estimate with just line stats? Is it possible to be around the 1900 - 2000 kbps mark or is it more realistic to be getting about 1700-1800 kbps?

I would also like to know what ISP's currently do Annex M? The information I searched for says Entanet, Plusnet Business but is that it? If so, what suppliers still use Entanet?

The only one I know a lot about is Be LLU, where everyone reckons the cut-off point is about 16Mbps download speed. So you are just above that.

At 16Mbps it comes out at not much upload increase, but 2.5Mbps download decrease!

That's because the way Annex M works is to take the lower part of the downstream frequencies and use them for upstream. Those frequencies provide a lot of the downstream capacity, and it seems the higher frequencies are so attenuated at the attenuation that results in 16Mbps down that they can't compensate for the loss.

For some reason as well, when those lower frequencies are used for upstream, they too attenuate so much as to provide little .

The higher the original Annex A downstream, the more benefit you get on upstream, and the less you lose from downstream. IIRC once the original Annex A downstream is above 20Mbps you get 2Mbps or more upstream and no downstream loss.

Re ISPs, Be as mentioned - on their Pro product, AAISP via both BT-based and Be-based I think, vivaciti are still Entanet resellers, as are Aquiss. I have a feeling Eclipse may do Annex M as well. There are probably others but those spring to mind.

The download does not concern me at all. It could be a 5 Mbps drop and I would be fine.

I realy just want the extra upload for my Flash Media Encoder streams. No matter the settings they all just look average. An increase in say 500 kbps from Annex M is a huge boost in quality.

Out of interest I plugged in my old Speedtouch 585 and got a good surprise, upload wise. An increase in 47 kbps.

Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 1,223 / 15,347
Data Transferred (Sent/Received) [KB/KB]: 4.00 / 3.00
Output Power (Up/Down) [dBm]: 12.0 / 0.0
Line Attenuation (Up/Down) [dB]: 13.5 / 23.5
SN Margin (Up/Down) [dB]: 6.0 / 6.0

How on earth can my Netgear be 28 db on download and 23.5 here? I did use custom firmware on my Netgear to mess with the synch but can I expect the 1900 kbps mark now for Annex M?

I sync roughly the same 16500 on my netgear dgn 2000 when i swap to annex m i get roughly 2200 upload and 16000 down on the BE 3db profile with gaming mode enabled. or 14300/1900 on the standard profile.

Expect is the wrong word to use, since until you try annex M it is largely estimates and guesswork.

In reply to a post by MrSaffron:

Expect is the wrong word to use, since until you try annex M it is largely estimates and guesswork.

My line is stable on annex A; and when I enable Annex M it disconnects all the time - and here are my stats:

DSL Type: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 1,321 / 17,076
Output Power (Up/Down) [dBm]: 12.0 / 18.5
Line Attenuation (Up/Down) [dB]: 12.5 / 24.5
SN Margin (Up/Down) [dB]: 7.0 / 6.5

In reply to a post by epyon:

I sync roughly the same 16500 on my netgear dgn 2000 when i swap to annex m i get roughly 2200 upload and 16000 down on the BE 3db profile with gaming mode enabled. or 14300/1900 on the standard profile.

The 3dB profile being an extremely important factor there, which the OP may not kow much about. Your standard 6dB figures illustrate exactly what I was telling him, and which could very well not be workable on his line.

On Annex M I mostly get 2450 upstream and 20000 down on the sync. The highest I've had is around 21500 and 2560.

My attenuation fluctuates between 15 and 18.

Take a look at the speed test result in my signature.

I currently don't have Annex M as I don't need it, but I'll get it back when MW3 comes out, you've gotta love being host.

Oh and I'm on BT 21cn, I can't get BE, but if you can I highly recommend it over 21cn.

Edited by deleted (Sun 16-Oct-11 14:31:33)

But the OP has attenuation of 28dB and sync'ed at about the best possible for that on a standard sync-time noise margin. So we don't want him thinking he is going to get your sorts of speeds, with your 18dB .

On the other hand yours is another post that shows the importance of the attenuation, and ties in with what I explained to him.