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jhlundin
join:2012-05-29

jhlundin

Member

[Speed Problem] Very choppy DSL connection-off/on-with very regu

I am having difficulty with ATT getting this problem diagnosed and fixed (5 calls and 2 onsite visits)... I am quite sure that a knowledgeable DSL tech will look at this and go: 'sure, I have seen this before... it is _______'

You might want to skip to the attachment, but I will give you the details too:

Basic problem: DSL connection fluctuates from 6M to 0M on a very regular basis (about 3-5 seconds on and about 10-15 seconds off...
6.0 ATT DSL in San Jose, CA
Sam problem occurs with:
-two different modems (motorola 2210 and Netgear DGND3300)
-three different computers (all that I have tested) operating Windows XP, Vista, and W7

Took one modem off site with one of the tested computers to be sure that it did, in fact, work under a similar line and network situation... it performed flawlessly.

Here are the statistics from the Netgear:
System Up Time 01:01:24
Port Status TxPkts RxPkts Collisions Tx B/s Rx B/s Up Time
WAN PPPoE 60849 103903 0 1733 38377 01:00:42
LAN 10M/100M 113539 61938 0 38780 2045 01:01:21
WLAN 11M/54M/270M 4558 2120 0 602 91 01:01:02

ADSL Link Downstream Upstream
Connection Speed 6016 kbps 768 kbps
Line Attenuation 23.0 db 12.0 db
Noise Margin 17.3 db 19.0 db

Sooooo far ATT has switched me over to another pair which had no effect...

Please let me know if I can supply any additional info... Thanks, John

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

d_l

MVM

Re: [Speed Problem] Very choppy DSL connection-off/on-with very

Those stats aren't showing any DSL layer problems. In fact they look so excellent right now, there is nothing to diagnose.

Can you capture stats that show slower sync speeds?
jhlundin
join:2012-05-29

jhlundin

Member

Click for full size
here is this morning's pattern
Click for full size
here is a tracert showing 3rd hop timeout
Thanks d_l, I know that the stats don't show any issues with the connection even when it is pegged at 0mb, my question is why is the connection going to zero then back so regularly and so predictably on all my computers from my connection to AT&T and not from any other connection to AT&T? Please see the images I have included... There is something in the pattern that will suggest some intermittent failure at some point in the network... Thanks, John

....well, now that I upload two images, I may not have uploaded the original image... very sorry... I will do that from the other computer, J
jhlundin

jhlundin

Member

Click for full size
Click for full size
...and here is the file that I neglected to upload yesterday (from a different computer)

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

d_l to jhlundin

MVM

to jhlundin
John, is this speed slowdown occurring while connected by wireless? If so, have you tested with a wired connection??

Could you try a gateway ping test to check if there is a problem between your computer and your AT&T gateway? »SBC DSL FAQ »How do I do a gateway ping test?
jhlundin
join:2012-05-29

jhlundin

Member

upper images are wireless, lower images are wired.... Although these are both Vista PCs, I have the same issues with my XP and Win7 PCs... I took the Vista notebook with the Motorola 2210 to a friends and tested their line and did not have any problems.
jhlundin

jhlundin to d_l

Member

to d_l
Click for full size
gateway ping test from wired
here is gateway ping test and ping test to the router on the 4th hop...
jhlundin

jhlundin to d_l

Member

to d_l
Click for full size
d_l, ...whatever you did, my data was uninterrupted (at about 1.5mb/s) for about 10 minutes at 8:40 Pacific time... first time that has happened since I have been collecting data... now it is *back* to the old problems... but the 4th hop in my tracert has cleared up (but the trace is going through a different router: 12.122.114.9)

...and everything is on and off (mostly off) again...

...and the ping to the 4th hop router is losing packets...

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

d_l to jhlundin

MVM

to jhlundin
Don't worry about the 4th hop router IF there is no packet loss form it to the the end router. The 4th router has been set to give low priority to direct ping packets, BUT it will pass through pings as fast as possible.

The gateway ping test should do at least 100 pings to get a valid set of statistics on the connection. You did have one high latency ping out of those four. That may indicate a problem with intermittent latency spikes which could slow throughput.
jhlundin
join:2012-05-29

jhlundin

Member

Again thanks for your help... two additional observations:

1-when doing speed tests the download # is all over the map (from 17kb/s to 3.15mb/s) but the upload speed is quite constant 0.61-0.63 suggesting that it is the download only that is having a problem.

2-the extended ping test:
Ping statistics for 99.35.135.254:
Packets: Sent = 331, Received = 329, Lost = 2 (0% loss),
Approximate round trip times in milli-seconds:
Minimum = 11ms, Maximum = 101ms, Average = 12ms

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

d_l to jhlundin

MVM

to jhlundin
The ping test showed some, but not major problems. Normally a serious speed loss will have higher avg latency or serious packet loss at the gateway or end router.

I really suspect your AT&T gateway router as the problem cause, but it would be nice to see more definitive proof. You could try the evaluation copy of PingPlotter (its a also good program to own): »SBC DSL FAQ »How do I set up and use PingPlotter to record network problems? A long period of pings (5 mins) to your gateway could show if the latency or packet loss is periodically "pulsing".

I had that happen once for a few days. The latency would spike up to over 1000 ms and the download speeds were dropping to nil during those spikes. The DSL was basically unusable during the problem.
jhlundin
join:2012-05-29

jhlundin

Member

Click for full size
three separate downloads with NO interruptions!
Thanks for all the help... the 3rd ATT technician came about an hour ago, looked at all my data, did some ping tests, called the "office" for about 30 minutes and all was right!! Said they reconfigured a "router in the east bay"... I always knew it was on the ATT side, but most the techs wanted to point to me when I had evidence to the contrary... Again, Thanks & Best regards, John

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

d_l to jhlundin

MVM

to jhlundin
I figured it was your gateway router that was the problem. Like I said before, I saw this myself once.
jhlundin
join:2012-05-29

jhlundin

Member

...Just so AT&T knows why I am unhappy with their DSL technical support, I have summarized the whole adventure in my blog (in case anybody is interested...).

But I feel much better!

»jhlundin.wordpress.com/2 ··· problem/