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Confuzzle

join:2007-11-21
California

[Speed Problem] High Latency and Slow Speeds

I have had the Pro plan for nearly 2 years and never had a problem until a few weeks ago when my connection started dropping randomly. An ATT tech came out checked my phone box outside (NID?) and whatever it is that sends the signal to it, Both were good and functioning properly. Long story short turns out it was a timing? CRC exit code error that was cleared up over the phone and now my line no longer has errors either.

Now I have slower speeds and bad latency that gets worse in the afternoons. This is a tracert I ran to google just now

Tracing route to google.com [74.125.224.164]
over a maximum of 30 hops:

1 2 ms 1 ms 1 ms 192.168.1.254
2 65 ms 64 ms 60 ms adsl-69-108-95-254.dsl.irvnca.pacbell.net [69.108.95.254]
3 66 ms 106 ms 78 ms 12.83.78.105
4 110 ms 64 ms 66 ms 12.123.132.217
5 62 ms 64 ms 62 ms 12.91.217.158
6 68 ms 74 ms 78 ms 209.85.248.185
7 111 ms 82 ms 60 ms 72.14.236.11
8 64 ms 64 ms 78 ms lax02s01-in-f4.1e100.net [74.125.224.164]

Trace complete.

and this was earlier in the afternoon,

Tracing route to google.com [173.194.37.71]
over a maximum of 30 hops:

1 2 ms 1 ms 1 ms 192.168.1.254
2 129 ms 131 ms 117 ms adsl-69-108-95-254.dsl.irvnca.pacbell.net [69.108.95.254]
3 73 ms 76 ms 74 ms 12.83.78.109
4 322 ms 301 ms 452 ms 12.123.132.217
5 96 ms 79 ms 87 ms 12.91.217.158
6 99 ms 106 ms 74 ms 209.85.248.185
7 74 ms 100 ms 86 ms 64.233.174.192
8 317 ms 350 ms 474 ms 72.14.239.82
9 454 ms 474 ms 442 ms 66.249.94.25
10 124 ms 136 ms 125 ms 64.233.175.94
11 149 ms 220 ms 120 ms atl14s08-in-f7.1e100.net [173.194.37.71]

Trace complete.

This is the wireshark ftp test (sorry I have no clue how to display images).
»i.imgur.com/erIsQ.png

I took this screenshot of my DSL statistics about 7 months ago in order to compare them with a D-Link router
»i.imgur.com/3fTWm.jpg

and these are my DSL stats now.
»i.imgur.com/DqELd.png

I have read a post on these forums where someone from the Midwest was suffering from these symptoms, It turned out to be that his upstream was being "challenged" and it was fixed by having his profile reloaded. As you can see my upstream margin has taken a massive hit (dropped by 10!) and is apparently a sign of "challenged" upstream. Do you guys think that could be happening to me? or is the problem something else?

Thanks for reading/helping :)



d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
kudos:7

It looks like you might have two different problems. You definitely have a DSL layer problem where your attenuation has increased from 7 months ago. At that time your Pro speeds were on the ragged edge of acceptable operation.

I suspect that AT&T placed your circuit on interleaved mode after the truck roll to clear up CRC errors and sync drops. I'm guessing that your attenuation might be increasing slightly in the afternoons to cause your sync speed to train down or maybe you simply have a train downs due to increased line noise in the afternoons. Could please you post a set of sync stats from the morning when your sync speeds and throughput should be better to verify this?

Could you run and post gateway ping tests: »SBC DSL FAQ »How do I do a gateway ping test? during the time you think the speed is working correctly and when you think you have a slowdown?

The wireshark graph looks ok, not perfect, but good enough, so I'm not convinced there is significant problem there. I've seen similar looking graphs that were collected on circuits that were considered to be operating well.
--
TCE Weather


Confuzzle

join:2007-11-21
California

These are the stats,
»i.imgur.com/sRHku.png

gateway ping,

Ping statistics for 69.108.95.254:
Packets: Sent = 100, Received = 100, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 46ms, Maximum = 52ms, Average = 48ms


and pathping taken immediately after re-sync at 7am.

Tracing route to 69.108.95.254 over a maximum of 30 hops

0 192.168.1.67
1 192.168.1.254
2 69.108.95.254

Computing statistics for 50 seconds...
Source to Here This Node/Link
Hop RTT Lost/Sent = Pct Lost/Sent = Pct Address
0 192.168.1.67
0/ 100 = 0% |
1 0ms 0/ 100 = 0% 0/ 100 = 0% 192.168.1.254
0/ 100 = 0% |
2 48ms 0/ 100 = 0% 0/ 100 = 0% 69.108.95.254

Trace complete.


Today I waited for what was occurring every time I had max speed but as time went on nothing happened, I do still have slightly higher latency than I used to (10-20ms more) but I have managed to sync at max speeds all day today without a disconnect. Unfortunately I might not have access to electricity for the following 2 weeks due to remodeling so I might not be able to continue monitoring the line until after it's all done.

Here are the DSL stats of a re-sync that was dropped on Thursday.
»i.imgur.com/hbS1r.png

On Thursday morning I reset the broadband link and watched it re-sync with those stats it lasted until the afternoon. When surfing, The internet started becoming more and more sluggish and suddenly the connection was lost then reconnected at lower speeds. I decided to leave it alone to find out if the speed was making it drop the connection or not, It remained stable.

Do you think whatever was wrong is now fixed?

I'll monitor the line more when I can and update on whether the line worsens or continues to remain stable. Thanks for helping. :D

P.S. I also did a throughput test immediately after re-sync this morning.
»i.imgur.com/QNevH.png



d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
kudos:7
reply to Confuzzle

The gateway ping test is fine. Your line definitely looks interleaved with those higher first hop latencies.

The throughput test is good.

Everything looks good for now except those modem stats. It looks like your upload sync dropped to 128 yesterday. That might suggest a modem dying problem. Maybe you could borrow a modem and test your connection stability with it.

Good luck with the renovations.
--
TCE Weather


Confuzzle

join:2007-11-21
California

I haven't been able to use the internet much but today as a website was loading my internet connection suddenly dropped for the first time since I re-synched the connection. There was no latency build up like in the past either it just suddenly dropped and returned a few times, Here are the assorted stats I managed to nab before I had to step away.

Gateway Ping
Ping statistics for 69.108.95.254:
Packets: Sent = 100, Received = 100, Lost = 0 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 58ms, Maximum = 67ms, Average = 62ms


Pathping
Tracing route to 69.108.95.254 over a maximum of 30 hops

0 192.168.1.67
1 192.168.1.254
2 69.108.95.254

Computing statistics for 50 seconds...
Source to Here This Node/Link
Hop RTT Lost/Sent = Pct Lost/Sent = Pct Address
0 192.168.1.67
0/ 100 = 0% |
1 0ms 0/ 100 = 0% 0/ 100 = 0% 192.168.1.254
0/ 100 = 0% |
2 62ms 0/ 100 = 0% 0/ 100 = 0% 69.108.95.254

Trace complete.


Stats
»i.imgur.com/5TdWs.png

DSL Diagnostics
»i.imgur.com/eEYCQ.png

How do I fix the interleaving problem? (is it a problem)

I have been using my old SBC 1070-B router to gather statistics and troubleshoot my line, I'll switch back to my Netgear though and see how things go with that.

I'll post an update when I can, Thanks.



d_l
Barsoom
Premium,MVM
join:2002-12-08
Reno, NV
kudos:7

1 edit
reply to Confuzzle

Interleave mode is allowing you to connect with a Pro profile. Without it, you could probably only connect reliably at Basic speeds.

The bottom line is that your attenuation is really too high for Pro speeds so you will periodically have speed train downs or sync problems. I wonder if your attenuation jumped for some reason after AT&T sold you the Pro speeds? I didn't think that AT&T would sell Pro knowingly with a loop as long as yours.

Those latest modem stats suggest that your low upload speeds may be caused by anomalously high attenuation in the upload frequencies. Your attenuation at 300kHz is higher that the overall attenuation for all used frequencies. I've never seen that before.

A slow upload speed like you are currently seeing could definitely slow down your browsing speeds. When you try to download anything with those upload speeds, your computer probably can't respond fast enough with ACK packets. This would make downloading seem sluggish.

I think that you should post in AT&T Direct: »AT&T Direct and let the techs there look at your line stats. Good Luck.


Confuzzle

join:2007-11-21
California

Sorry this reply took such a long time but remodeling is taking a lot longer than originally planned (nearly almost done now). There was no difference when using my netgear router though.

When I switched to pro AT&T said I was just on the borderline of pro speeds and suggested we "give it a shot" to see if the line could take it. In the 2 years since then I have never had as much as a slowdown in speed or slight latency issue with the line, It has been rock steady until now. Seems that I'm not the only person experiencing troubles that lives in the Los Angeles County/Orange County area either so maybe something went wrong with a server or maybe there was an overload due to summer heat and more people on?

I will make a topic in the AT&T Direct forums as soon as the remodeling is done (won't be long now I hope) and also include a link to this thread. Thanks for all the help again.


Confuzzle

join:2007-11-21
California
reply to Confuzzle

Turns out my high latency and slow speeds (and connection drops) were a phone line problem. After hearing noise (a PFFFFT sound like someone ripping paper and a phone ringing) on the line I scheduled a phone line repair and the tech that came said that there were a few crossed wires and extra wires, It's been a few weeks now and everything has been working normally (except for a connection drop every 2-4 days that last a few secs). So thanks to all that helped and remember to listen for sounds on your phone line also plug your router/phone directly into the NID if possible to see if conditions improve.