Here is a very basic but essential suggestion. I have been having problems with a Speedstream 5360 modem from eBay. It was working fine, then it locked up. The WAN led on the router went out, indicating it had lost connection to the modem.
TekSavvy support said Bell Canada had lost three area codes in Ontario. All the DSL modems gave timeout errors and nobody could connect. My area code was among them. After the Bell problem was fixed, I assumed that was the cause and continued on my merry way.
But the same wall plug also powered the UPS for my entire computer.
The UPS had a habit of sounding an alert from time to time. I figured it was a power problem upstream since I live in a small town far from the nuclear plants in Pickering.
Yesterday, I happened to have the main electrical panel removed to add a new circuit. While moving the wires, the UPS gave another alert.
You guessed it. The neutral (white) wire went under a clamp screw that had never been tightened. The wire was just resting against the metal.
Checking the other connections, I found several more that were never properly tightened. Now the lights in the bathroom seem much brighter, and they don't flicker any more.
So I had fooled myself into believing the random system problems were somewhere else and out of my control. My guess is the Speedstream modem got a bad glitch and hung. It is working fine now. The Bell problem was just a coincidence, and had nothing to do with the real problem. All this was very poor troubleshooting technique on my part.
If you have nothing to do some day, and are familiar with working on AC line voltages, you might check the connections in your panel and see if any are loose. You might find some that were never tightened properly and have worked loose over the years. The same applies to wire nuts and the screw connections in wall sockets.
It only takes a couple of minutes to check, but it could save many hours tracking down random system problems.
The 5360 is not a very good DSL modem. There's no status information available so troubleshooting line related problems is difficult. Connection issue require numbers, such as the line levels, signal to noise ratios, etc. I suggest you replace it with a 4100, 5100B, or later DSL modem that provides web based diagnostics.
Incidentally, please lose the right justified formatting and indented margins. It looks nice with the proper proportional fonts, but looks awful with monospaced font. Most usenet readers use monospaced.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
I already have the update but was reluctant to apply it since it was not clear if it was needed. Do you have any information on what problems it is supposed to fix?
This is a cheap backup modem from eBay in case the main one dies. TekSavvy can retrieve all the line information if needed, and they say all the data is exceptionally good.
The switching office is less than two blocks away, so the SNR is excellent. I checked the speeds using different online DSL speed checks, and they all agree it is running about as fast as the connection allows. My neighbour has some more expensive modems and he gets the same results.
Just for you, I'll make this post in XNews. But it won't have any spell check, urls, or references from other sources.
Also, I have a problem with your links that are surrounded with "". This makes it difficult to copy and paste the url from an editor to the browser window.
Other than that, I really do appreciate your posts. They are on-topic, full of very good information, and you usually include references for follow-up if needed. I think you set a very good example for the others. Thanks.
No real data but I have a guess as to what it fixes. The obvious one is that 10/100 full/half duplex detection is broken. I had some random short term ( < 5 sec) disconnects that went away with the update. Some of my customers have experienced occasional loss of sync problems with long lines (12K to 15K feet) that was also reduced. I tested a 5360 at home with the help of my ISP. They obtained stats from the DSLAM before and after the update. They were greatly improved in terms of staying connected after the update. My guess(tm) is that there were some parameter tweaks to more closely resemble what's found in the real world. I also did some bench testing to see if various modems can handle 6Mbits/sec. Most could but the 5360 was a bit flaky. It would sometime retrain the line for no obvious reason. I don't recall if that was with old or new firmware, probably old as I did it long ago.
That's not what I found with a before/after test. Got any numbers? Incidentally, I have an Acterna/JDSU HST-3000a tester. Some results from typical lines:
The various graphs and tables from "JV" are before and after results found after re-routing the inside wiring and replacing the microfilter mess with a splitter at the MPOE. It sorta worked both before and after, but the numbers improved dramatically after rewiring. That's roughly what I've been finding as I go around testing everyones DSL lines. Lots of problems with inside wiring and microfilters.
Hmmmm... Not good. Any chance you're suffering from a "disturber" signal in the same bundle? I had interference problems from a mess of T1's that were sharing the same bundle for about a mile. However, it showed up in the error rate and a very erratic looking channel response graph (that I forgot to save).
Your story about the loose neutral wire is interesting. We had an earthquake in 1989 that jarred loose all kinds of underground wiring. In one case, the neutral wire for a large electronics manufactory was lost at the xformer. Of course, the phases were not balanced and resulting in brownouts or burnouts depending on location. I've had a similar problem at my house, where the combination of an unbalanced load and an inadequate high resistance neutral wire resulted in some odd effects. The only real clue was that there was a loud 60Hz buzz when a high current drain appliance would kick in coming from the copper water pipes under the house. Since the neutral wasn't carrying the current, the water pipes were trying to do its job, and buzzing. I measured about 3A AC current around the water pipes with a clamp on ammeter. I'm sure it was more as there were multiple paths to ground. Congrats on analyzing and fixing the problem.
Thanks. I appreciate it. Content before form is good.
True. However, it prevents Forte Agent from word wrapping the URL's and also blocks the URL into a clickable link if there are some odd characters, such as parenthesis) in the URL. I've experimented with various ways to insure that the URL is mutilated by the news software and the method seems to be the least disgusting.
Thanks. Oh-oh, you've been reading my stuff. That usually causes brain damage. If you dig more carefully, you'll also find that they're also mixture of guesswork, satire, humor, and anecdotes. Try not to take anything I write seriously.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
[...] >> I already have the update but was reluctant to apply it since it >> was not clear if it was needed. Do you have any information on >> what problems it is supposed to fix?
The modem seems to be running fine after fixing the loose connection. I'll keep monitoring it, but if it ain't broke, don't fix it:)
[...]
I'm not sure what you mean by a "before/after test". Yes, I have the Teksavvy numbers around someplace, but I don't know where I put them. They did the test several times while I was fixing TCP problems on Win98. Each time they remarked how good the numbers were.
In the meantime, here's some runs I just took using the test on
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Chicago : 4316 Dallas : 3740 Hamilton : 4227 LA #1 : 3560 LA #2 : 3717 LA #3 : 3540 London : 3273 Toronto : 4229 Vancouver : 4090 Denver : 1953
These were taken while listening to streaming classical music from DR Klassisk, in Copenhagen. That eats 128k:
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NetStat shows the instantaneous rate can vary quite a bit:
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but the results are very similar to what my neighbor gets down the hall.
Overall, I'm quite satisfied with the performance. TekSavvy advertises 5 MB for their DSL, and I'm getting pretty close to what I pay for:
formatting link
The graphs are too small to tell what is happening. I couldn't get much information on the tests it makes, but the spec looks interesting.
What causes the problems and why does rerouting fix them?
As for as the wiring here, it enters the building from underground, then goes directly to the switch panel. From there, I believe it goes through pipes to the different apartments. The building is constructed with 10.5 inch thick prestressed concrete beams 4 feet wide. Any holes cost a fortune to drill, but I think the power lines are routed through individual aluminum pipes to each apartment. This would provide good shielding from spikes on the power lines. I don't know how the telephone lines are routed, but it is very unlikely that I could do anything about it if there were a problem. But they seem to be fine.
Yes. I did have problems before while I was on dialup, and they gave me to a new pair. Then DSL came to town and I finally switched over after everyone else in the apartment started getting reliable results.
Incidentally, the Bell installer did measure the performance of the line withan instrument similar to yours, and he said the numbers were very good.
Thanks.
The whole point was to indicate we tend to take things for granted.
Sometimes it pays to look under the rug and find out what uglies are lurking there:)
I wonder if you haev any problems reading newspapers? Or IEEE articles? Maybe datasheets or app notes? Pretty much anything in pdf files is right justified. There's a good reason for this. It greatly speeds reading text since you don't have to track the edge of individual lines. Your eyes can take in one or more lines at once, without wasting time fooling with the right margin. That's why newspapers and professional articles have been right-justified for centuries.
I also find it makes my notes much easier to read. But I wrote my own editor so I get the advantages of being able to make it do whatever I need.
There were also some oddities with other special symbols in the URL, but I can't seem to find any examples.
Try indenting a URL with a few spaces such as:
formatting link
As I recall, sometimes it works but sometimes it wraps. I'm not sure what controls it.
Incidentally, you're using Forte Agent 4.1 while I'm using 4.2. At some point in the distant past, Forte would wrap all URL's, but apparently that was fixed in subsequent versions. I've been using for so long, that I don't recall when.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
When you come across a link that is too long, or so badly done that you cannot predict what will happen in different clients or browsers, you owe it to your readers to go out of your way and fix those kinds of problems.
Many people might be very interested in what you have to say, but maybe they are not skilled enough in the ways of the web to figure out how to fix those kinds of problems. But you can, and save everyone a big headache from wasting time on those cases. That's exactly what TinyUrl and all the other sites are for.
I find email clients start wrapping at column 70 or so. If a reply is quoted, it adds two or three characters to the beginning. This often makes the line long enough to wrap, and urls are probably the most likely to get garbled. But a TinyUrl link is very short, so it will probably survive in the longest thread.
Now you can guarantee your links will survive, and you no longer need the "" separators. That will save you time as well as your readers. So be kind to your readers, and use TinyUrl for any link longer than 50 characters or so.
Golly, I think I just persuaded myself to do the same thing:)
Good philosophy. I'm a bit more ambitious as I find my luck seems to be better with continuous upgrades to the latest greatest firmware, drivers, versions, and such, than to let things stagnate. Chances are higher of discovering a problem with old firmware, than with new.
Before updating the 5360 firmware. The ISP and AT&T distributed a considerable number of Efficient 5360 DSL modems. They were OK for their day (about 2003) but started showing problems when higher speeds and DSLAM upgrades started appearing. I was trying to determine if it was a problem with this particular modem. The usual symptom was "It's been working fine for xx years, but now the sync lite goes on and off".
Try:
Good enough. I never could get much more than 3500 out of the Efficient 5360 DSL modems. Looks like some users are getting 4 to 5 Mbits/sec. You might want to try their test (without the background music):
The graphs are what I can get out of the tester. Interpreting them requires more skill and experience than I currently have. I can see gross line issues (loading coils, bridged taps), and inside wiring nightmares, but above a minimum level of line quality, they don't show much. There's quite a bit of useful info in that mess, but it has to extracted from among the duplicated and obscure information. The important items are the maximum rates (up/down), the associated capacity percentage, the noise margins, signal levels, and attenuation. Also, line length. The fast quality check are the two capacity percentages. Low numbers are better. For example:
shows 17,700 ft, which well beyond the 15,000 ft limit. As a result, the downstream capacity is a 84%, which means he can't go much faster that 1Mbits/sec on that long line.
The problems with inside wiring are the side effects of the spaghetti wiring topology. Wires can be either bus or star topology. Some are unterminated, which look like a capacitor. Some have shorts or leaks to ground or conduit resulting line balance problems. I'm also beginning to suspect that there are some differences in quality between brand of microfilters. The lines tend to run next to power lines, resulting in noise pickup. CFL lamps seem to be a problem. Usually, these only cause problems when you're at the line length limit (15,000ft), but even the best of short lines can be trashed by interference or an imbalance.
The HST-3000b has a built in TDR (time domain reflectometer). The pulse width is too wide to show anything less than a few feet (I forgot the exact number) from the tester. However, when I use it to test inside wiring, it shows every rotten connection, flaky microfilter, bridged tap, and broken wire. I can't use it to reverse engineer the topology or locate specific devices, but it's a great quality control test to see whether the inside wiring might be an issue. Again, I'm still learning to interpret the data.
The problems usually start at the MPOE (minimum point of entry) also known as the NIU (network interface unit) or demarc (point of demarcation). One side is the responsibility of the telco and is usually in good shape. The other side is the responsibility of the property owner, which is usually a mass of spaghetti wiring.
It's odd that you would have a problem so close to the CO (central office). My guess(tm) is that your line goes well beyond your building from the CO. The way it works is that the telco does NOT run a pair directly from the CO to your building. They run a mass of 100 pairs (or more) down the poles or through the underground conduit to as far as 3 miles away. Your pair is just a tap off this bus which is a bridged tap.
Your line could also have entered several other buildings further downstream. Lots of ways to create problems.
The tester has a go/no-go check for installers. I don't use it because it will pass a really marginal line. The installer usually tests the line from the MPOE, not from the DSL modem, since they're only really responsible for the telco part of the puzzle. The problem is usually between the MPOE and the DSL modem, which may not have been part of the test.
If you had a better DSL modem, with internal diagnostics, you could have obtained the line stats yourself. Incidentally, look on eBay for an Efficient 5260. It has a huge amount of built in stats and diags. I used one for line testing before I bought the HST-3000b. See:
Also, I just received a new battery for my tester that includes a serial port suitable for driving a printer. (Don't ask me why they put the serial port in the battery). The installers used to carry a printer and leave a printout of the line stats in the phone closet. Locally, they don't do that any more, but I plan to resurrect the practice.
Not me. I'm a classic paranoid and am ready and willing to blame anyone and anything for my problems. What I find amazing is that after doing this for so many years, I can almost guess what's wrong from the general symptoms, usually without any troubleshooting or even a complete description.
None of my customers will pay me to do that.
Nope. Page formatting has been tested many times in the past and found to be a minor issue to reading accuracy and speed as compared to font selection. The reason we have to live with printed columns came from Gutenberg and movable type. The wide page formatting and wooden page forms of the day was causing serious problems with getting lines of type to stay straight. There's nothing aesthetically worse than a wiggly line of text. So, Gutenberg or one of his contemporaries solved the problem by cutting the line into individual parts and using columns. They were still crooked, but it was difficult to tell. Right justification made the columns look even nicer. Look at prints of the early bibles for examples. Unfortunately, they didn't fix the form alignment problem for many centuries, so we're stuck with columnar text apparently permanently.
Well, there's much to be said for readability and formatting. It does make thinks easier to read. However, I try to stress my content and will only go so far as trying to be "neat" with my formatting. Usenet is about content, not advertising, wiggly icons, ransom note font selection, avatars, and other garbage commonly found in blogs and web based forums. That's why I lurk on Usenet, and not in the blogs and fora. Just estimate the actual content per screen for a typical web forum, versus the same for Usenet and methinks you'll see the problem.
Because I'm lazy. Most of my rants contain about 5 URL's. Shortened URL's are somewhat of a time burner for me. Actually, I've never even used a short URL. Nobody has ever suggested that I should, until now.
--
Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Now I remember. I formatted the above to look like:
Try indenting a URL with a few spaces such as: url-starts-here...
For some unknown reason, Forte decides to convert that to a left justified URL, and adds a blank line above it. As I recall, if there were any more indented URL's on subsequent lines, they would display correctly with an indent and no extra line. I bug reported this years ago, but nothing ever happened.
Methinks I'll continue to use which eliminate all these oddities.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
Yes, I know. Teksavvy suggested the same one. Unfortunately, it requires Java. I run Win98 with 2 gig partitions for DOS. I don't have Java installed, and there's not enough room on the hard disk.
So I have to pass on that one:
Looks like most people are getting around 4300KB, the same as me. I am pleased you found that link. Now I can sleep nights, knowing I'm just about average:)
[...]
Thanks for the explanation. I'm amazed the problems can be so bad.
[...]
Yes, we use the term demarc here in Canada. But the wiring was done very professionally, as was most everything else. The only thing is they forgot to tighten some clamp screws in my breaker panel:)
Yes, I know how the lines are run. This particular run is very short. It only goes from the main office to this building, then terminates in a subdivision a short distance away. Midland is quite small, so there's not many places you could go three miles and not end up way out in the country side:)
But that's the second time I had problems with a pair. I understand about half the lines have drops that were never disconnected.
No, he had a much more comprehensive test. Recall I'm in Canada, and way out in the boondocks. So the procedures are quite different here.
Funny you should mention that. My main modem is a 5260.
Unfortunately, I was never able to get into the modem and do anything, so I had to rely on TekSavvy to get the readings from their end. Like most people, I thought the 5360 would be an improved version. It looks very much the same, but actually has less capability than the previous model. But they both work fine, given the very short run and excellent SNR.
Sounds like you do a lot of this kind of work.
Very good. Now you can impress people with magic and charge accordingly:
You do realize that the worlds supply of white space is limited? If you continue to consume white space by indenting your entire posting, we may eventually run out of white space and allthewordswillruntogether.
Borrow a real computah. Besides Java, some of the benchmarking programs use Flash.
I beg to differ. I see plenty of 5 and 6Mbit/sec reports on DSLReports. You were getting about 20% less. I suggest you retest and rethink your numbers.
They're not that bad. Most of the DSL modems work just fine but at reduced capacity. As long as the subscribed rate cap is fairly low (i.e. < 3Mbits/sec), only those users at the extreme end of the line will see problems with inside wiring problems. The DSL adaptive equalizer and echo canceller circuits are very good at compensating for bad lines both inside and outside. What I found amazing was the number of installation I've seen where the owners were perfectly happy, but the tester showed that they could do better.
This was done by "professional" PBI/SBCGlobal/AT&T installers over the years:
Note that the upper half of the picture disappeared. It looked much like the lower mess in the photo. Several days work and much swearing later, it looked like this:
My office wiring closet is much the same, after years of "professional" installation work by trained and qualified installers.
Bingo. That's the usual problem. In the above phone room, I had problems with a few pairs. I knew that the adjacent office building had bridged pairs from the same bundle. They were also my customer so I traced out the pairs (they were labelled) on the telco side. Lots and lots of unterminated pairs. I didn't have time to deal with their mess, so I just disconnected the affected pairs. The problems instantly went away.
So much for standardization. I have no idea how it's done outside of the Monterey Bay and Smog Angeles area. I've seen both extremes. I've seen super qualified installers with 20+ years of field experience. I've also seen clueless nitwits, with zero experience, minimal training, and a very defensive attitude. Also, everything in between. My favorite was the installer that was so stoned, that he left his tools scattered all over the building.
Telnet to 10.0.0.1 and dig out the stats and diags.
Incidentally, if you find a 2-wire modem/router, they also have some useful stats:
Also, this is roughly what the ISP gets from AT&T:
Bigger model numbers do not always mean a later or better version.
Not really. My guess is that DSL re-installs and troubleshooting accounts for about 10% of my income. One of my problems is that whatever I'm doing for work seems to vary radically from month to month. That's great for variety (I get easily bored) and entertainment value, but I never have time to get really good at what I'm doing.
It's perfectly acceptable to believe in magic. Just don't try to rely on it for doing repairs. I've learned to make my initial guess, and then keep my big mouth shut about it. I then use conventional troubleshooting methods to isolate the culprit. I haven't kept score but my batting average seems to be quite good. One of the secrets of doing repairs is knowing when to give up or not even try. That also enhances my batting average.
Charge accordingly? Damn... I knew I forgot to do something.
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Jeff Liebermann jeffl@cruzio.com
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558
I had a problem like this with my dishwasher. It starting failing at the same point in the cycle, intermittent at first, then all the time. Not wanting to bother troubleshooting myself I called a repair dude who promptly replaced the main control module and all was good (he left me the old module). A few days later it fails again, same problem. I swapped back the old module and problem remained. Repair dude comes back and finally figures it out after a lot of frigging around. Yup, you guessed it - bad contact on the back of the mains wall plug, allowing operation at low currents, but fails at higher currents (like when the heater comes on I guess). Socket must have always been like that since I moved into the place. The tech playing around with the mains plug was enough to fix it for a day or two.
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