premio
join:2002-02-17
Antelope, CA
| [Speed Problem] Horribly unreliable DSL in Sacramento, CA.. help
My line has been mostly rock solid for 4 years at elite speeds. Lately I am experiencing horrible internet connections. Nothing has changed in my house, the modem syncs at 6016/768.
Symptoms: DSL state drops and then reconnects, when connected periods of extended packet loss (against SBC dns servers and google). So basically layer 3 and 4 issues making for increased frustration.
Below are some details:
----
I see these a lot on the 5100b log:
2009/07/10 02:59:38 GMT E |DSL |HYBRID 1
2009/07/10 02:59:38 GMT E |DSL |Link up 77 US 768 DS 6016 (FAST:G.dmt)
2009/07/10 03:02:03 GMT E |DSL |State: DROP
2009/07/10 03:02:03 GMT E |DSL |DataPump Version - 01.01.00.00
2009/07/10 03:02:03 GMT E |DSL |Link Down
2009/07/10 03:02:03 GMT E |DSL |State: WAITING
2009/07/10 03:02:19 GMT E |DSL |State: INITIALIZING
tech readout:
Rx Tx
140 Current Rate 6016 768
141 Previous Rate 0 0
142 DSL Max Rate - -
143 DSL Min Rate - -
144 Current ATTN DR 6016 -
145 Current SNRM 7.0 16.0
146 Current LATN - -
147 Current SATN 40.0 -
148 Current TP - 5.5
240 LAN IP Tx 75828524 0 58786 147 0
241 LAN IP Rx 3328335 0 4 35577 0
242 LAN Ethernet Tx 76074777 0 58786 132 11
243 LAN Ethernet Rx 3470659 0 35577 4 0
244 LAN PPPoE Rx - - 0 0 -
245 IP 2684 Tx 2593287 0 34334 0 0
246 IP 2684 Rx 73897584 0 56715 0 0
247 Ethernet 2684 Tx 3944627 0 34414 0 64
248 Ethernet 2684 Rx 75608918 1250 56856 0 0
333 Receive SNR ps
333a
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
333b
0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0 0.0
333c
0.0 0.0 0.0 0.0 0.0 0.0 7.5 7.0 8.5 8.5 8.5 8.5 9.5 9.5 8.5 9.0
333d
9.5 9.0 9.0 9.0 9.5 9.5 9.5 9.5 9.0 9.5 8.0 7.5 7.5 8.5 9.0 9.5
333e
0.0 9.0 10.0 9.5 9.5 9.0 9.5 9.5 9.5 8.5 9.0 9.0 9.5 9.0 8.5 8.5
333f
8.5 34.5 8.5 8.5 8.0 9.0 9.0 8.0 8.5 7.0 7.5 8.0 8.0 8.5 7.5 7.5
333g
7.5 7.5 8.0 8.0 8.0 8.0 7.5 8.0 7.0 7.0 7.0 8.0 8.5 7.5 7.5 7.5
333h
7.5 7.5 7.5 7.5 7.5 7.5 7.0 7.0 7.5 7.5 7.5 7.5 7.0 8.0 8.0 8.5
333i
7.0 8.5 8.5 7.5 7.0 7.5 7.0 8.0 7.0 8.0 8.0 7.5 8.0 8.0 8.0 8.0
333j
8.0 8.5 9.0 7.5 7.5 8.5 7.5 0.0 7.5 7.5 7.5 8.0 7.5 7.5 8.0 7.5
333k
7.0 8.0 7.5 7.5 8.0 0.0 7.5 7.5 7.5 7.5 8.0 7.5 9.0 7.0 7.0 7.0
333l
7.0 7.0 0.0 7.0 7.0 7.5 7.0 7.0 7.0 7.0 7.5 7.5 8.0 7.5 7.5 7.0
333m
7.0 7.5 7.0 7.5 7.5 7.0 7.5 7.0 7.0 7.5 7.0 7.5 7.5 8.0 7.5 7.5
333n
7.0 7.5 7.0 7.0 8.0 8.0 7.5 8.0 0.0 7.5 8.0 7.5 7.5 7.5 8.0 7.5
333o
7.5 8.0 7.5 7.5 7.5 7.5 7.5 8.0 7.5 7.0 7.5 8.0 7.5 7.5 7.0 8.0
333p
7.0 7.0 7.0 7.0 7.5 8.0 7.5 0.0 0.0 0.0 7.5 7.5 7.0 8.0 7.0 0.0
334 ADSL DMT Bin Bits
334a
0 0 0 0 0 0 0 8 9 9 10 10 10 10 10 10
334b
10 10 9 10 10 9 9 9 9 9 9 9 9 9 0 0
334c
0 0 0 0 0 0 8 8 8 9 9 9 9 9 9 9
334d
9 10 9 9 9 9 8 8 8 8 8 6 7 8 8 8
334e
0 8 9 9 9 9 9 9 9 9 9 9 10 10 10 10
334f
10 2 11 11 11 11 11 11 11 12 12 11 12 11 11 11
334g
11 11 11 11 11 11 11 11 11 11 10 11 11 11 11 11
334h
11 10 11 11 11 10 10 6 10 10 10 9 9 10 11 10
334i
10 10 9 11 10 10 10 10 10 10 10 9 9 8 9 8
334j
5 6 7 8 8 5 2 0 5 8 8 9 9 6 6 8
334k
8 8 8 6 2 0 4 7 7 7 8 7 5 7 8 8
334l
7 5 0 2 5 7 8 8 6 8 7 6 5 7 7 5
334m
7 7 7 5 8 8 7 5 7 7 6 7 7 7 5 7
334n
6 7 6 6 6 6 5 4 0 2 5 5 6 6 6 6
334o
5 6 7 7 6 5 4 5 5 6 6 6 5 6 5 5
334p
5 5 5 3 2 2 2 0 0 0 2 2 4 3 2 0 |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| Re: [Speed Problem] Horribly unreliable DSL in Sacramento, CA..
Could you please run your techreadout through this tool and post the results here?: »SBC DSL FAQ »How can I check for the maximum attainable sync speeds with a 5100b/4100 modem? We can't do that from what you have posted as it must be parsed from html format. Also was the techreadout that you posted from a problem period or a good period? Could you get DMT charts from each time?
During a problem period have you repeatedly checked the lines 163 to 174 on the techreadout page to see if those error counters are rapidly incrementing indicating either a problem with RFI or impulse noise interference? |
|
premio
join:2002-02-17
Antelope, CA
| It's been awhile, I forgot about that cool program. Results are posted below. Looks like 163 is showing 10% errors over 24hr? yikes. I called SBC and they told me it could be until next friday/saturday to have someone look at it.
161 Chan Received Blks 43130 731312 0
162 Chan Transmitted Blks 43131 731312 0
163 Chan Corrected Blks 681 73689 0
174 CVL Tx 59 2001 0
Downstream Current Rate (Reported): 6016
Downstream Maxrate (Estimated): 6024
Downstream Bit Margin (Calculated): 460
Upstream Current Rate (Reported): 768
Upstream Maxrate (Estimated): 1013
Upstream Bit Margin (Reported): 96
Bit tones with notches/missing bits:
bit(s) 38 163.875 - 168.1875 KHz
bit(s) 40 172.5 - 176.8125 KHz
bit(s) 57 245.8125 - 250.125 KHz
bit(s) 59:60 254.4375 - 263.0625 KHz
bit(s) 65:76 280.3125 - 332.0625 KHz
bit(s) 78:85 336.375 - 370.875 KHz
bit(s) 87 375.1875 - 379.5 KHz
bit(s) 91 392.4375 - 396.75 KHz
bit(s) 113 487.3125 - 491.625 KHz
bit(s) 119:121 513.1875 - 526.125 KHz
bit(s) 123:128 530.4375 - 556.3125 KHz
bit(s) 130 560.625 - 564.9375 KHz
bit(s) 132 569.25 - 573.5625 KHz
bit(s) 134 577.875 - 582.1875 KHz
bit(s) 144 621 - 625.3125 KHz
bit(s) 146 629.625 - 633.9375 KHz
bit(s) 148:154 638.25 - 668.4375 KHz
bit(s) 158 681.375 - 685.6875 KHz
bit(s) 162:167 698.625 - 724.5 KHz
bit(s) 172:180 741.75 - 780.5625 KHz
bit(s) 188 810.75 - 815.0625 KHz
bit(s) 191 823.6875 - 828 KHz
bit(s) 195 840.9375 - 845.25 KHz
bit(s) 199 858.1875 - 862.5 KHz
bit(s) 202:203 871.125 - 879.75 KHz
bit(s) 206 888.375 - 892.6875 KHz
bit(s) 210:211 905.625 - 914.25 KHz
bit(s) 213:222 918.5625 - 961.6875 KHz
bit(s) 224:225 966 - 974.625 KHz
bit(s) 229:230 987.5625 - 996.1875 KHz
bit(s) 245:251 1056.5625 - 1086.75 KHz
bit(s) 255 1099.6875 - 1104 KHz |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| reply to premio
I'm not very good at visualizing those missing notches without seeing the actual chart. It looks like there are a lot of them, but mostly they are narrow ones. They don't seem to be perfectly evenly spaced; however, the chart sometimes can give a different impression than the simple "numbers".
Those are a lot of CVLs and even a few on the transmitted side. |
|
premio
join:2002-02-17
Antelope, CA
| reply to premio
does this work?
»/users/deblin/···aph=true |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
2 edits | reply to premio
Yes, much better. 
A lot of those notches are only one or two bits deep. The typical harmonic interference problem has the notches evenly spaced and deep, say all the way to zero or at least down to only two bits.
This looks like a board spectrum of very low intensity noise overlaid on your DSL signal. Have you introduced any new electronic or electrical (like a motor) devices in your place since the problem began? Are you in a single family residence? If not, then one of your neighbors might have added some device?
Edit: Oh yes, if you haven't figured it out already, those excessive CVLs (CRC errors) are causing the packet loss. |
|
premio
join:2002-02-17
Antelope, CA
| It's a single family house, with just a naked DSL running through the wires. I have an external keptal at the NID. Right now I'm rock solid again, but I know I'll go through a flaky period again.
ATT called me back to tell me my appt was no Wednesday to look at the RT card. maybe its just exhibiting signs of failure.
 thanks for looking/helping. |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| reply to premio
Recently we had someone report a problem with symptoms a lot like yours. Their chart showed harmonic notches but they weren't as strong as some others we've seen. They hadn't added any new devices, but it turns out they had moved their modem next to their aquarium pump in the kitchen. Noise source solved. |
|
premio
join:2002-02-17
Antelope, CA
| Interesting. The RF was causing the problems? I do have my 2.4Ghz wifi router, which I turned up the signal strength on, a 1.9Ghz phone, and a 2.4Ghz GPRS device in the same vicinity. I think I'll try moving the mode.
Why would RF by indicated? |
|
d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
| reply to premio
You can check, but I don't think those devices would be causing your problems IF they are working correctly (within FCC specs). We've never heard of anyone having interference problems from those types of devices before and I'd think your phone data cable (a flat satin cable at that) would practically have to be wrapped around one of those devices to have any interference. |
|
giraffedata
join:2009-07-11
San Jose, CA
| reply to premio
Who said anything about RF (radio frequency)? Or did you mean EMI (electromagnetic interference)?
The aquarium pump presumably was generating electromagnetic waves in the frequency range of DSL, which imposed themselves on the DSL wires and corrupted the real DSL signal. The clue is deep regularly spaced notches (frequencies where the line isn't able to transmit much information) in the frequency graph (showing the achievable data transmission rate in each of the DSL frequency bands).
As you see in the postings above, DSL uses frequencies up to about a megahertz. Radiation in the radio frequency region, such as a cordless phone or wifi, are way above this and the DSL equipment easily filters it out. |
|
tonydi
Premium,MVM
join:2001-05-11
San Jose, CA
1 edit | While those particular devices aren't in the "RF" range, certainly things like radio stations can be below the 1MHz range. It's not uncommon to see RF interference from nearby stations show up in the DMT graphs. |
|
premio
join:2002-02-17
Antelope, CA
| I'll just wrap the modem in tinfoil
ATT finally came out and said the wires are out of sync? Whatever the measurement taken was 40 on one wire and 65 on the other. Is that resistance, the amount of hops, or what?
It's strange that my friend 20 miles away is having issues with connectivity on his new circuit, and I'm having the same on an old proven circuit.
What did Uverse do??? |
|
premio
join:2002-02-17
Antelope, CA
| reply to premio
Well the removed the excess bridge taps a few weeks ago, all was well with my 20ms ping to google and yahoo. but...
WTF am I going to do with this? You guys are the experts, is Uverse killing what has been the best internet connection for me over the past 10 years?
1 1 ms 1 ms 1 ms 192.168.100.1
2 1 ms 1 ms 1 ms 192.168.0.1
3 115 ms 100 ms 102 ms adsl-71-142-255-254.dsl.scrm01.pacbell.net [71.1
42.255.254]
4 122 ms 127 ms 201 ms dist2-vlan50.scrm01.pbi.net [64.171.152.67]
5 168 ms 200 ms 110 ms 151.164.98.66
6 193 ms 101 ms 100 ms 151.164.38.152
7 161 ms 198 ms 104 ms po5-3.core01.sjc04.atlas.cogentco.com [154.54.13
.97]
8 139 ms 107 ms 200 ms te9-2.mpd01.sjc04.atlas.cogentco.com [154.54.0.1
73]
9 135 ms 222 ms 183 ms 38.104.140.46
10 100 ms 199 ms 201 ms google.navigation.opendns.com [208.67.219.230] |
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