TilhasBB
Formally Goden99
Premium
join:2000-08-05
canada
| reply to metalhawk
Re: Losing Sync
I dont have a full understanding of it yet But
0F:
01 = bitswap on, trellis off
02 = bitswap off, trellis on
03 = bitswap off, trellis off
bitswap tries to maintain an acceptable snr for each bin does that by swaping bins.
trellis... no clue..... yet  |
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avernar
join:2002-05-23
Mississauga, ON
clubs: | Trellis Coded Modulation (TCM) is a modulation scheme that allows faster transmission using the same bandwidth with less errors.
When I turn off TCM here I loose 2-3dB of SNMR. |
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TilhasBB
Formally Goden99
Premium
join:2000-08-05
canada
1 edit | 0F=01
0F=02
0F=02
low = -1db???
Humm...
but my line is stable so i can't really tell if it helps or not.
So 02 is what should be tried for stability? |
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avernar
join:2002-05-23
Mississauga, ON
clubs:
| I'm trying with 02 right now and I'll see how my line graph looks like tomorrow. Technically, 00 and 02 should be better than 01 and 03. From what I've read about TCM is that it's more resistant to noise.
On your stats you gained 4dB SNRM and 1270kbps of max channel capacity by turning TCM on. On my 3meg line this is what I got:
0F SNRM RCO
00 14.0dB 87% (3457kbps)
01 12.0dB 85% (3425kbps)
02 14.0dB 88% (3418kbps)
03 12.0dB 85% (3463kbps)
I've have to do more research on bitswapping to see how it can be a good or bad thing. |
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TilhasBB
Formally Goden99
Premium
join:2000-08-05
canada | best is to use ADSL monitor on each setting and see which has the lowest # of errors. |
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avernar
join:2002-05-23
Mississauga, ON
clubs:
| Just read some stuff about bit swapping. It's usually a good thing as it lets the modem adapt to changes in line noise. There are situations where the bit swap protocol can't keep up if the noise spectrum changes too often.
Also, if there are problems in the upstream channel it can cause the bit swap commands from the modem to the DSLAM to be missed. Without interleave the modem can't easily detect when the DSLAM didn't get the command. |
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losrobos
join:2005-01-24
Guelph, ON
| Just chiming in ,I had the Bell tech show up sunday(no phonecall first)and checked both jacks being used,trimmed wires and reconnected.He had to go down the street to the box to finish repairs.Now I'm on 5056 Interleaved and still getting errors.Adsl monitor didn't want to work for me so I managed to find similar software(Routerstats 2.7i) from a UK dsl site called (dslzone.uk).Had it running in about 5min and it's very customizable |
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TilhasBB
Formally Goden99
Premium
join:2000-08-05
canada | losrobos> I am getting errors as well. But are you losing sync?
check your pm. I have a new firmware to try |
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losrobos
join:2005-01-24
Guelph, ON | RE TilhasBB_I'm not losing sync but have over 45,000 downstrem FEC errors after 14 hrs runtime.I'll check the v4 firmware tomorrow |
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TilhasBB
Formally Goden99
Premium
join:2000-08-05
canada
2 edits | losrobos> the one in your pm.
Make sure you restore factory defaults before because your going to an older firmware.
Well I think its safe to say this firmware rocks
which you can get here
»m8s-rates.com/speedtouch/routers···revious/
Look at the graph i've never had any other firmware hold my snr so stable AND almost no errors |
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avernar
join:2002-05-23
Mississauga, ON
clubs:
| reply to losrobos
45000 FECs are a lot but they're not errors, they are the number of CRC errors that would have happened if you were on fast path. On interleave the FEC algorithm has corrected those packets.
How many CRC errors did you get and how many errored seconds do you have in that same 14hrs runtime? |
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