I got an update, either a fault has started on my line, or another install has hit me noticebly.

When disabling my tbb graph I noticed my latency jump up at 3am, and some packetloss at 5pm yesterday, checked the modem data and was a burst of crc errors lasted an hour or so. (silent noise no affect on snrm)

Was calm until 9.57am this morning and now getting FEC's in the 1000s although no crc's at all there is clearly something disruptive whether its crosstalk of a new line or a fault.

sync is now down to 62mbit as a result of the FEC overheads. so now approaching 45% lost signal.

--edit--

Bear in mind this may be a fault not crosstalk so has been raised with isp now.

Edited by Chrysalis (Wed 08-Jan-14 19:08:11)

I lost 10-12Mb/sec over about 3 months (from low 70s down to lower 60s), recovered a bit when something was upgraded in the cabinet relatively recently (about the same time as modem firmware updates were reported but I don't use the BT modem), currently syncing around 64 down, latency also increased over the initial months from below 10ms initially to over 20ms now.
Fritz!Box now has vectoring enabled firmware so just waiting for vectoring to be enabled at the cabinet (fingers crossed).

TP-Link TL-ER5120. 2 Openreach modems feeding it, it does PPPoE.

Hits around 124Mb down and 27Mb up on speed tests to a single machine. Tricky to get both WANs maxed at once.

In reply to a post by adslmax:

Not fastest enough! Mine is 128/12

Just for you, Phil. Excuse the poor upload, speed tester doesn't seem to like the load balancing too much.

http://www.speedtest.net/result/3219692669.png

Sorry to be slow posting this information; it took a while to get back to my historical data.

First, I posted here about my experiences of "attainable bandwidth vs crosstalk" last year.

In that post, I described how my attainable bandwidth dropped steadily over the life of a (long) connection, making it appear that crosstalk was increasing. However, a resync restored the level of the attainable bandwidth back up by 10Mbps. The thoughts of the forum then were that gradual bitswaps were having an effect.

I now have more data that I can add to the situation: Since that post, I have suffered one period where DLM intervened and added FEC+interleaving, and have had the firmware updated. Now, I don't seem to see the same kind of gradual drift in attainable speed.

Date      Attain Actual SNRM
01/2012   90     40            * On 17a profile, but only 40/10 package available
02/2012   91     40
02/2012   85     80     7.3dB  * 80/20 package turned on
03/2012   84     80     7.1dB
06/2012   83     80     6.9dB
07/2012   82     80     6.6dB
09/2012   82     80     6.5dB  * Voice fault occurs around here
11/2012   81     80     6.3dB
12/2012   78     80     5.4dB
01/2013   76     80     4.6dB
05/2013   72     80     3.0dB  * Immediately before resync
05/2013   83     80     6.7dB  * Immediately after resync (1st for 6 months)
05/2013   79     80     5.6dB  * one week after resync
05/2013   77     80     5.1dB  * two weeks after resync
06/2013   76     80     4.6dB
06/2013   75     80     4.3dB
07/2013   74     80     3.9dB  * stopped monitoring sync status for a while, until...
10/2013   86     75     5.9dB  * After DLM turned on FEC+interleaving; new firmware
11/2013   83     80     7.2dB  * DLM removed FEC+interleaving
01/2014   82     80     6.9dB  * Immediately before a resync
01/2014   82     80     7.0dB  * Immediately after a resync (1st for 2 months)

Since the firmware update, my "attainable" has stayed remarkably consistent.

The firmware update has made things very consistent for me also

In reply to a post by adslmax:

In reply to a post by Ignitionnet:

I'm getting a second line installed early next week and bonding them together to deliver about 150Mb down, 38Mb up,

VDSL cannot do bonding together.

Interesting *looks at said option on a customer site*

My max attainable going back 2 and a half years was 135Mbit, its now 110Mbit.

between september 2012 and now i have lost around ~6mb of the ~76mb i started with now syncing at 70.97 with 66mb speedtests. bt wholesale website still says i can manage the full 80/20 (i do get the 20 up) as indeed the fttc cab is 60 metres to the left of my house and the distance to the old cab is even shorter at about 40 metres, line goes from cab to top of pole about ~25 metres then the dropwire is about 15 metres to the roof the a further 5-6 metres to the master socket in the living room

could there be a possibility of some damage to the cabling around the fftc cab or elsewhere between me and it?

a few weeks ago the council decided to widen the road around the cab and redo footpaths surrounding the cab there is no grass between cab and path just tarmac that was dug up and replaced

im more than happy with what i have but i could of been getting 75-75mb throughput

Assuming I have no line fault this is my values.

Installed as 1st on cab 18th Feb 2014, distance 350-450 M from cab.
max attain: 83mbps down 24mbps up
sync: 74mbps down snrm 7db 20mbps up snrm 7db

5 days after installation:
max attain: 78mbps down 21mbps up
sync: 76mbps down 20mbps snrm 6.5db up snrm 7db

10 days after installation:
max attain: 74mbps down 21mbps up
Now DLM kicked in INP 3 , delay 8ms and interleave 1399 down , fast up
sync: 67mbps down snrm 6db 20mbps up snrm 7db

11 days after installation:
max attain: 72mbps down 21mbps up
DLM still active as before but interleave down to 1341
sync: 66mbps down snrm 6db 20mbps up snrm 7db

Today (28 days after installation):
max attain: 69mbps down 21mbps up
DLM as before (INP 3 delay 8ms)
sync: 62mbps down snrm 5.5db 20mbps up snrm 6db

So I have lost around 20% in total speed in 4 weeks as a result of crosstalk and
DLM interleave settings.

I am unsure how many are connected to the cab now but have read that the take up in this area is 3 times the national average so it could be quite a few. The cab
supports a total of 329 properties.
Lets hope it stops now as I am heading for Infinity 1 speeds in about 2 months at this rate.
BT - can we please have vector support soon to deal with all this crosstalk !