Unexplained drops in sync speed

[greglloyd]

Hi All,

Can anyone shed some light on why my sync speed might be dropping?

1) My max attainable rate is around 43500

2) My system usually maintains a very stable 42000 connection (Have had Infinity for 2 years or so now with Option 2 from day 1).

3) Yesterday I noticed the sync speed dropped to 39997 (I'm still showing on the BT page as on Option 2)

4) This morning to my horror it has now dropped to 34996

5) My usual SNR Margin is 6db. However, yesterday it was just over 7db, and this morning it is now 9.9db!

6) Im still on fast path, no interleaving, no delay, and my error counts are low - so its not like the cabinet was detecting issues and taking action to stablise the line?

7) No wiring in the house has changed

😎 The speeds above are the actual sync speeds that the modem is connection to the cabinet at - not speed test results from online.

9) Nothing has changed with equipment, cabling, or the master socket in the house. Simply a drop in sync speed from the cabinet.

So in the past 48hrs I have lost approx 7 meg off my sync speed which is considerable on a 42 meg connection to start with (17% drop in speed). I concerned now as I may see further falls in speed and either way, we all know that BT Infinity takes a very long time to bump your sync speeds back up.

p.s. If any mods are reading this I would appreciate if you could contact me to discuss. An engineer call out may be required.

[Bullitt]

what modem is giving you snr numbers?

[greglloyd]

The standard one via telnet (from a Mac)

[Bullitt]

can you access the modem web interface?

[greglloyd]

Yes. That's where I can see the stats from. See below :-

[Bullitt]

you could try this then

go to basic then wan
click on the line with tr069_internet
remove the tick on wan connection enable
press submit
go to advanced then qos
remove the tick on enable
go to advanced then cwmp
remove the tick on periodic inform enable
remove the tick on enable certificate
press submit

[greglloyd]

Didn't make a difference unfortunately.. Disabled the wan connection for TR_069 - all other settings were already as you suggested. Sync is still being capped at 34996 with a 10db snr margin. It's as if I've been put on a banded profile at the cabinet for no good reason (All line stats look good and I'm on fast path. Had 42 meg for months and months with issues).

[Bullitt]

anything in the log?

[greglloyd]

Hi. I don't have logging enabled in the modem. I think I will enable logging and ride this out for a week or two and see if the DLM does any further adjustments. 

Does anyone know what the time frames are for target SNR changes on Infinity? With ADSL you could see a profile change within 3 days and a target SNR decrease within about 7 days. However, with Infinity I've a bad feeling it could be much much longer.

Does anyone know if the DLM on Infinity makes adjustments every 7 days or so, or is it longer?

[Bullitt]

enable logging and you may see earlier entries