Speed dropped how!!

Hi I have had a fairly good speed with BT, sync'ing over 2mb. I decided to order BT Vision but I was told that my line was only capable of 1Mb. So going to the stats on the hub I told the lady what it said and it was around 2.5mb.

My Vision box was sent out on a subject to survey basis. When it arrived it went through the setup and all was well. For the next 3 weeks we enjoyed the on demand service. then my hub re-synced.

I have phoned the help desk but all I get is you can only support 1Mb so vision will not work! But it was working I was getting 2.5Mb connection.

BT voice say there is no fault on my line I'm at a loss. I dont have the actual stats from before I got vision because all was well and good I'm about 3.5km from the exchange but my line stats are rubbish and I have a lot of FEC errors.

Here's my stats this is plugged into the test socket which makes no noticable difference to the speed I have an engineer installed face plate fitted about 3/4 years ago. hope you can help

Mark

Link Information


Uptime: 1 day, 15:58:13

Modulation: G.992.1 annex A

Bandwidth (Up/Down) [kbps/kbps]: 448 / 1,120

Data Transferred (Sent/Received) [MB/MB]: 57.06 / 469.98

Output Power (Up/Down) [dBm]: 12.0 / 16.5

Line Attenuation (Up/Down) [dB]: 31.5 / 61.0

SN Margin (Up/Down) [dB]: 16.0 / 12.0

Vendor ID (Local/Remote): TMMB / TSTC

Loss of Framing (Local/Remote): 0 / 0

Loss of Signal (Local/Remote): 0 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): 0

Error Seconds (Local/Remote): 0 / 0

FEC Errors (Up/Down): 0 / 11,507,519

CRC Errors (Up/Down): 0 / 70

HEC Errors (Up/Down): 0 / 59

Line Profile: Interleaved

If your target noise margin was 6dB previously I suspect you would have got the 2.5Mbps, but some thing has happened to make things unstable and you now have a 12dB target noise margin, hence slower speeds.

The massive number of FEC errors is the clue that something is up.

You don't happen to be using the power plug networking units that come with the vision box?

Yes I am. Please dont tell me they cause interference!!!
Not with the vision box though I've just put a small server in a small office so used them to link it up.

They have been known to casue problems!
Try removing them and then reboot the router and check the stats again.

The other thing I don't understand is if what mr saffron said is right and my snr goes back down to 6db and I get 2.5Mb why do BT think I can only recieve a maximum of 1Mb.

off to unplug my adapters.
Cheers
Mark

I've just unplugged the powerline adapters but I still seem to be getting the fec errors. Any other ideas.

Link Information


Uptime: 0 days, 0:02:18

Modulation: G.992.1 annex A

Bandwidth (Up/Down) [kbps/kbps]: 448 / 1,376

Data Transferred (Sent/Received) [KB/KB]: 21.00 / 12.00

Output Power (Up/Down) [dBm]: 12.0 / 17.0

Line Attenuation (Up/Down) [dB]: 31.5 / 61.0

SN Margin (Up/Down) [dB]: 17.0 / 12.5

Vendor ID (Local/Remote): TMMB / TSTC

Loss of Framing (Local/Remote): 0 / 0

Loss of Signal (Local/Remote): 0 / 0

Loss of Power (Local/Remote): 0 / 0

Loss of Link (Remote): 0

Error Seconds (Local/Remote): 0 / 0

FEC Errors (Up/Down): 0 / 33,885

CRC Errors (Up/Down): 0 / 0

HEC Errors (Up/Down): 0 / 0

Line Profile: Interleaved

Edited by wher2guv (Sat 24-May-08 15:18:27)

In reply to:

---

why do BT think I can only recieve a maximum of 1Mb.

---

Because your line sync is 1376Kbps, which equates to a 1meg profile.

33,885 FEC errors in just over two minutes is not good, and is clearly evidence of a problem somewhere. By comparison;


DSL Connection

Link Information

Uptime: 47 days, 0:05:47
Modulation: G.992.1 annex A
Bandwidth (Up/Down) [kbps/kbps]: 448 / 8,128
Data Transferred (Sent/Received) [MB/GB]: 993.72 / 3.04
Output Power (Up/Down) [dBm]: 11.5 / 19.5
Line Attenuation (Up/Down) [dB]: 15.0 / 27.0
SN Margin (Up/Down) [dB]: 24.0 / 6.5
Vendor ID (Local/Remote): TMMB / ALCB
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 0 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 15 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 0 / 8,328
HEC Errors (Up/Down): 0 / 5,076

I have apparently none, after 47 days. Is there any way you could borrow a different router and check that its not your home hub causing the issue ?

Zarjaz,
you have no fec errors since your line is not interleaved

(clue is no fec errors, confirmation is: sync 8128)
you do still have some errors on the line. (crc and header )

regards
Ggremlin

Yes I realise my line sync is correct for a 1Mb line but Up until about a week and a half ago I was sync'ing at 2.5Mb sufficient for BT Vision to work and receive the on demand programmes but BT reckon my line will support no more than 1Mb. I had a pretty reliable connection until then.

It wont make any difference what BT think, as long as your line is synced below 2272 and has a 2000k profile on demand will work.

Thank you, I was aware of that, I was trying to highlight that the amount of (any) errors in that length of time is not good.