ADSL Max Speeds - Update.

Hi again.

Just an update, and some further advice needed.

Everything is now fine, and line constantly synched at 8128 down, and 448
up. Speeds are variously between 5.5-6.2/6.3 Mbps, depending on time of
day. Stats are as follows:

Atten: 19db down, 5.5 db up
Noise Margin: 17db down, 27 db up

Have had no loss of synch events according to router logs, although I am not
convinced about that. First query is shouldn't my line now try synching at
a lower rate, as clearly the data throughput wont support the current synch
rates? I thought this was what happened during this initial period, but
mine is always synched at the highest rate. My stats suggest there is
plenty of headroom in terms of SNR, so could support more throughput, but
they are clearly not going to let that happen (I don't pretend to understand
how that works...!).

Also, AIUI, my line rate will not be "locked" after this initial 10 day
training period, and will in fact always synch at the highest stable rate,
and allow data accordingly? The only reason for this process now is to
allow BT to set a fault reporting rate, should my speeds drop in future. Am
I correct in this assumption?

Finally, does all of this look normal, in terms of others experiences with
Max product?

Thanks in advance folks.

Ian

On Tue, 27 Jun 2006 08:52:19 +0100, "Mr Wiffy"
<(E-Mail Removed)> wrote:

>Hi again.
>
>Just an update, and some further advice needed.
>
>Everything is now fine, and line constantly synched at 8128 down, and 448
>up. Speeds are variously between 5.5-6.2/6.3 Mbps, depending on time of
>day. Stats are as follows:
>
>Atten: 19db down, 5.5 db up
>Noise Margin: 17db down, 27 db up
>
>Have had no loss of synch events according to router logs, although I am not
>convinced about that. First query is shouldn't my line now try synching at
>a lower rate, as clearly the data throughput wont support the current synch
>rates? I thought this was what happened during this initial period, but
>mine is always synched at the highest rate.

No.

It has no idea of what the data throughput possibility is, because it
cannot know whether you are attempting to pull data as fast as
possible.

The training is all done based on the SNR achieved. If you can get 8Mb
without the SNR going below 6dB, then you will get 8Mb synch speeds.

If you can't, then you will get whatever synch speed results in an SNR
of about 6dB.


>Also, AIUI, my line rate will not be "locked" after this initial 10 day
>training period, and will in fact always synch at the highest stable rate,
>and allow data accordingly? The only reason for this process now is to
>allow BT to set a fault reporting rate, should my speeds drop in future. Am
>I correct in this assumption?
>

More or less.

But if you have even one connection at a lower speed, then your BRAS
rate will be reduced to the next increment of 500Kb below the rate at
which you connected (minus "overheads").

Up to now, this has then remained at that rate until you have had
three full days of connecting at a higher rate again, but BT have
today announced limited changes to this system.


>Finally, does all of this look normal, in terms of others experiences with
>Max product?

You certainly have very good SNR figures.

Your throughput seems a little low for that synch speed, but there
could be a number of reasons for this.
--
Alex Heney, Global Villager
Never enter a battle of wits unarmed.
To reply by email, my address is alexATheneyDOTplusDOTcom