Two new lines... very different speeds :-(

Hi folks, I need a bit of advice please. I have had two brand new BT lines installed plus identical broadband packages with the intention of bonding the two lines. My confusion is that the two lines are running at very different speeds. One line is syncing at 9207kbps and the other at 3,722.

When I signed up for the broadband there was a discrepancy with the estimated speed 6.5 and 5.0 which the salesperson glossed over by saying the database wasnt very accurate... Now I am regretting not following this up at the time.

The lines are now active and have spoken with Zen whose immediate response was that the lines have only been active for 3 days and they need more time to settle. In my mind the discrepancy is so large that there must be a problem with the phone line.

Having completed the BT speed test and noting that they deem anything from 600-7150 to be acceptable I am concerned that I am never going to get the poor performing line up to speed. That is if there is a problem with the line.

The slow line has the following stats

Output Power (Up\Down) 12.5/19.0
Line Attenuation 19.0/41.5
SN Margin 5.0/6.5

The fast line has the following stats

Output Power (Up\Down) 12.5/21.0
Line Attenuation 19.0/39.0
SN Margin 6.0/6.5

Any ideas why the discrepany? Am I just being impatient and should wait or do you think there is a more significant issue? Any ideas how I should resolve it? If there is a problem with one line then ideally BT would come in and check the connection howevevr looking at over posts I feel like I have two hopes...

Thanks
D

Looks odd. The high figure is too high for standard ADSL, is your exchange enabled for BT's 21CN network? See http://www.samknows.com/broadband/search.php

Could you check each modem's mode, i.e. ADSL, ADSL2, or ADSL2+, look for something like g.dmt, g.992, g.995 etc.

Could you post each router's current stats, i.e. upstream/downstream sync rates, attenuations, SNR margins.

Do Zen offer bonding?

What routers are you using?

What happens if you swap them over?

Can you post the full stats?

There shouldn't be all that much between the lines, say 9.5 Meg vs. 8.5 Meg. The slower line is slightly longer, i.e. higher attenuation.

Bur as previous poster says, it is important to find out what ADSL Modes they are running.

Thanks for the responses!

As far as I am aware we should be on ADSL2+ (sry if i didnt make that clear) the exchange (high wycombe) is definitely enabled for 21CN and ADSL2+.

Zen dont do bonding. In their tests it didnt work so well so I am taking a little bit of a punt with bonding offered by Sharedband.

Unfortunately at the moment I am just testing with my own personal modem\router, Thomson\Speedtouch ST585v6. Once I am happy with the broadband then I hope to sign up with Sharedband who will then provide their own updated routers for the bonding.

On day one I was initially swapping the router between the two lines to get an idea of the speed. For the last 4 days ago I have left the router attached to the slow line in the hope it would adapt to a faster speed but it has got marginally slower. Tomorrow I am attaching an old netgear I have to the faster line to let that settle.

The stats from the Speedtouch ST585v6 are:

Line 1 - The fast one

Uptime: 0 days, 5:31:11
Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 872 / 9,207
Data Transferred (Sent/Received) [MB/MB]: 9.40 / 87.48
Output Power (Up/Down) [dBm]: 12.5 / 21.0
Line Attenuation (Up/Down) [dB]: 19.5 / 39.0
SN Margin (Up/Down) [dB]: 5.5 / 6.0
Vendor ID (Local/Remote): TMMB / TSTC
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 6 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 2,000 / 0
FEC Errors (Up/Down): 0 / 0
CRC Errors (Up/Down): 2,947 / 55,785
HEC Errors (Up/Down): 199 / 17,013

Line 2 - The slow one

Uptime: 0 days, 1:04:09
Modulation: G.992.5 annex A
Bandwidth (Up/Down) [kbps/kbps]: 666 / 3,692
Data Transferred (Sent/Received) [KB/KB]: 283.00 / 634.00
Output Power (Up/Down) [dBm]: 12.5 / 19.0
Line Attenuation (Up/Down) [dB]: 19.0 / 41.5
SN Margin (Up/Down) [dB]: 5.0 / 6.5
Vendor ID (Local/Remote): TMMB / TSTC
Loss of Framing (Local/Remote): 0 / 0
Loss of Signal (Local/Remote): 5 / 0
Loss of Power (Local/Remote): 0 / 0
Loss of Link (Remote): 0
Error Seconds (Local/Remote): 270 / 0
FEC Errors (Up/Down): 9,510 / 6,042
CRC Errors (Up/Down): 2,474 / 9
HEC Errors (Up/Down): 490 / 8

Hmm - "O2 / Be: Enabled" BE offer bonding. So do AAISP.

Yes, you're on adsl2+, but not on BE

Maybe noise on the line damaging your sync? For that attenuation, I would expect 8Megs and 12 Megs.

The slower line is interleaved, the faster line is fastpath.

The faster line has higher power too.

Lots of errors on the faster line.

I looked at BE and if they had offered a business specific product then I would have definitely been tempted. AAISP were out of my budget.

I wasnt aware of fastpath and interleaving but just had a quick read and maybe that explains the discrepancy then?

Alas am not sure if things are any clearer for me!

Edited by deleted (Wed 26-May-10 10:45:37)

Have you removed the ring wire and got filters on any phone equipment?

See http://www.dslzoneuk.net/socket.php?type=html

I'd be tempted to force each modem into g.dmt (standard ADSL) mode to see if that is more stable. There are lots of errors on your line to give that error second count.

Would the interleaving on one line explain the discrepancy in speed?

Is there information on the web that lists the key stats I have posted and what poor\acceptable\good numbers would look like?

I havent made any changes to the phone lines since they were installed. I assumed they should both be identical and I have tested them with exactly the same setups. Router, filter, cables etc.. There are no extensions or phones attached to the master sockets and one master socket is sat pretty much above the other so cant explain why there could be a difference in line length as one poster suggests.

Once both lines are stable (fingers crossed) and I feel comfortable with the performance then I may look at removing the bell wire.

Am thinking ADSL Max might be more stable but will wait until I really understand why I am getting the differences between the two lines.
I am concerned that the differences between the lines is going to cause big headaches later on if I bond them.

Also the info I have on bonding says differences in latency between lines can cause performance issues as the routers have to work harder resequencing data packets.

I am seeing a 16ms difference when pinging the bbc site. 10ms on the fast line and 26ms on the slow line.

At the moment I am still tentatively assuming that one of the lines has an issue (insert expletives) and pretty amazed that (insert expletives) BT can install two lines with totally different characteristics\behaviour. Hopefully I am being unfair (sorry BT please help me!) but am wondering how many folks out there are settling for rubbish performance when their next door neighbours are getting considerably better.

Thanks again and please let me know if you have any more ideas. I will update this thread with my progress.. fingers crossed!