I have set the Billion to a 6dB SNR target so that it can remain stable for a few days. If left in auto SNR it had taken the SNR down to 3dB without dropouts but increased error rates. I guess
The line attenuation has always been 57-58dB with the HH5 but the Billion appears to be giving 55-56dB so improving the line slightly?
Interleaving has always been used on this line.
What is INP sorry?
the attenuation difference is negligible and will not change your conenction speed interleaving is as high as it goes at 64 so must be correcting a lot of errors
right after 2 days and 20 hours the connection on ADSL2 has dropped. I have tried going back to ADSL and appear to be getting faster rates. Is this backwards step due to the poor line quality and the fact the line isnt good enough of ADSL2 or ADSL2+??
BT Wholesale Speed Test shows that there is still some margin, in theory, to improve the speed but even with ADSL i am still getting errors
1. Best Effort Test: -provides background information.
|0 Mbps||4 Mbps|
Max Achievable Speed
| Download speedachieved during the test was - 2.4 Mbps|
For your connection, the acceptable range of speeds is 1.2 Mbps-4 Mbps.
IP Profile for your line is - 2.51 Mbps
2. Upstream Test: -provides background information.
|0 Mbps||0.83 Mbps|
Max Achievable Speed
|Upload speed achieved during the test was - 0.44Mbps|
Upstream Rate IP profile on your line is - 0.83 Mbps
Router Data after 4 hours to show errors
|Model Name||BiPAC 8800NL|
|System Up-Time||0D 4H 20M 53S|
|Link Power State||L0|
|Line Coding (Trellis)||On||On|
|SNR Margin (dB)||6.9||7.0|
|Output Power (dBm)||17.9||12.6|
|Attainable Rate (Kbps)||2932||820|
|K (number of bytes in DMT frame)||90||21|
|R (number of check bytes in RS code word)||8||16|
|S (RS code word size in DMT frame)||2.00||2.00|
|D (interleaver depth)||16||2|
|INP (DMT symbol)||0.34||0.05|
|Super Frame Errors||648||7|
|RS Correctable Errors||867855||25|
|RS Uncorrectable Errors||1129||0|
Any suggestions to improve and are these error levels OK or not???
you may have change the mod but still looks like adsl2
your interleaving septh has reduced hence why errors have increased but as long as conenction stable and download speed consistent with profile then looks ok. from the stats your connection speed is almost at attainable so can't see any more scope at present
I agree with imjolly. You may have tried overriding the modulation mode to ADSL on the router-modem but it looks like the Openreach and BT Wholesale equipment doesn't care about that and you are on ADSL2/2+.
ADSL1 uses certain set down IP profiles that certain ranges of down connection rate map onto.
ADSL2/2+ uses a down IP profile that is set to 88.2% of the down connection rate. This is true in your case.
The max attainable connection rates will vary a bit and depends on conditions at the time when you view the stats. Similarly the actual connection rates will depend on the state of things at sync time.
You said earlier that on auto the noise margin dropped to 3dB. Auto may actually mean that it uses the targets set by the DLM. That's the normal process.
The DLM will reduce the sync time target to 3dB if the line is stable enough. A lower sync time noise margin will result in a higher connection rate. If however the sync time level was around 6dB and then it just dropped to around 3dB several hours later due to increased noise then that's a different situation.
Does your router record the sync time noise margins in the log?
The down IP profile limits your speed. I'm not sure why the speedtest result gives a range maximum of 4Mbps (rather than 2.51Mbps)?
It does a similar thing with my current ADSL2+ connection, but gives a range of 4 - 21Mbps.
Download speed achieved during the test was - 14.47 Mbps
For your connection, the acceptable range of speeds is 4 Mbps-21 Mbps.
IP Profile for your line is - 14.97 Mbps
and often with adslmax it shows 0.6 - 7.15mb