d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
1 edit | reply to falstaffpac
Re: Speed slower than expected (Elite)
I goofed. Don't know what I was thinking, but that 100-300 per something rate should have been in minutes, not hours.  I corrected that time interval in the post above.
Anyhow, your error count for 20 minutes of modem run time, would fit with known error rates for microfilter problems.
Your DMT chart looks fairly decent. There are minor notches that are probably due to local AM radio stations, but those wouldn't be generating huge error rates. Almost everyone has some of those. So there isn't any massive interference source showing up on the DMT chart.
Try changing the filters to spares if you have them. Also you might check your modem log to see which hybrid number it is using, e.g. +000 days 00:00:18 E |DSL |HYBRID 3: »192.168.0.1/log.htm
Edit: added info
I've had some data on download throughput speeds versus CRC error rates that I have sat on for a while while I've been trying to understand what it meant before posting.
The two curves shouldn't be interpreted to mean that the 1536 speeds are that much more resistant to slowdowns from CRC errors. I used two different CRC sources to generate errors and only one would affect the 1536 line. I discovered that there were different curves for the two speeds after I "broke" one error source so I couldn't delve into the explanation of this difference.
Anyhow you can see that high CRC error rates can effectively destroy your download speeds. |
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falstaffpac
join:2007-09-15
2 edits | Ok, I did a little experiment. As I outlined in a post above, I have a junction box, from the box I have:
Line 1 to the modem (no filter)
Line 2 to my phone, with a filter
Line 3 to my tivos, with a filter
I disconnected Line 2 at the terminal box and timed CRC errors for 1 minute:
CRC Error TO Modem/To Internet
START 1092 10
END 1205 11
+113 +1
I then disconnected Line 3 at the terminal box (now both Lines 2 and Line 3 are disconnected) and timed CRC errors for 1 minute:
START 1316 12
END 1422 14
+106 +2
I then re-connected both filters to their respective terminal boxes and get the following:
START 1762 19
END 1882 19
+120 +0
I also reviewed the log as you suggested, there is no hybrid entry. |
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falstaffpac
join:2007-09-15
1 edit | Ok, I think I'm in good shape now. I made a couple more wiring tweaks and swapped a filter. Now I have a filtered line to the modem, throughput 4.9Mbps I also did a 1 minute CRC check and have the following:
CRC Errors in 1 minute
TO Modem/TO Internet
START 97 3
END 145 4
+48 +1
Are 48 CRC/min errors acceptable? |
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