Theft ...

Someone has stolen 6 Mbps

On Monday, all was fine with a full 40 Mbps sync and speeds of 38Mbps - TBB, BT and speedtest.net all giving similar results.

Yesterday (Tuesday), I was doing a download and noticed the speed was a little slow, so followed up with a TBB test and it returned 31Mbps which was confirmed by speedtest.net. Did a few checks and rebooted the modem. Tested again with similar results.

Tried a BT speedtest and found my maximum throughput had dropped from 38717 down to 32xxx. Again went and checked everything, and still returning the slow speeds. BT ran a full set of diagnostics around midnight and reported no issues but could see that my sync and max throughput had dropped.

Nothing obvious here, external wires look OK, no roadworks from here to cabinet ...

Rebooted the modem again this morning and max has increased to 33978

But still scratching my head as to why the drop and why it has not recovered.

More users on your cabinet leading to increased cross-talk?

It's happened to me as users increased from 3 when I first got FTTC up to about 20 now... though I've only lost about 3Mbps.

Possible, but all in one step? I was the first in the cabinet and now up to around 30 without any noticeable changes.

My neighbour had his installation a few weeks back and we share a dropwire - no noticeable difference.

If it was another one or two installed, then it does not bode well for a full cabinet!

It's not easy to be sure because I also had another problem in the middle of it all, but it seemed to happen in one step for me.

Another big unknown of course is the DLM, it may have a long memory and be biding its time to catch your neighbour out

it does not bode well for a full cabinet!

No, it doesn't... but it's bringing peoples rates down towards those that the estimator gives, maybe they're based on a full(ish) cabinet?

It bodes even less well for the achievable speeds when BT uprate the cabs for 80Mbps, I'd guess that it's even more susceptible to crosstalk


eta: your comment that

In reply to a post by MHC:

Rebooted the modem again this morning and max has increased to 33978

could be indicative of cross-talk, I get a better sync if I reboot in the morning. I think a fair number of people turn the modem off when they're not using it, hence lower crosstalk.

Edited by billford (Wed 18-May-11 11:39:08)

You think people turn the OR modem off?

The HH or other router, possibly, but the modem I'm not so sure. I haven't done so since it was first connected, whereas I used to turn off my ADSL router every so often.

It's a pure guess... but it fits with getting better sync in the morning, and a lot of people are averse to leaving anything electrical running if not necessary.

Some want to "save the planet" and some think it's a fire risk (possibly with some justification going by recent reports!).

I'd start by getting the modem swapped. When the engineer comes to do this, make sure they test with their kit, and if seeing the 'original' full sync, ask them to get the sync rate reset via the helpdesk.

Asked about that last night - but there is "no fault" yet! Need to wait until it gets to 15000 !

The local Tech who seems to be doing most is quite good. He called in one day last week - wanted to park in my drive whilst he did an install next door (other side) rather than park on double yellows. No problem for me, as I know I'll get good service when he comes back to see me again.

I can also add to the original that I have even reduced the local RFI/noise close to the modem and across one drop wire by having my ISDN removed and replaced with PSTN. ISDN NTE went along with ISDN switch and small PBX.

How do you tell how many people are connected to your cab?

When the BT engineer comes round to fix a fault, you ask him