Losing internet connection during large downloads.

I've a hunch that you'll see something interesting in your modem logs: http://192.168.100.1/logs.htm and your signal levels may tell us something: http://192.168.100.1/signal.htm Bob

logs:http://192.168.100.1/logs.htm>

Thanks for the help Bob.

I checked the logs and here are the problems that seem to show up:

Downstream Value Frequency 643750000 Hz Signal to Noise Ratio 37 dB QAM QAM256 Network Access Control Object ON Power Level 9 dBmV The Downstream Power Level reading is a snapshot taken at the time this page was requested. Please Reload/Refresh this Page for a new reading

Upstream Value Channel ID 2 Frequency 31392000 Hz Ranging Service ID 27 Symbol Rate 2.560 Msym/s Power Level 37 dBmV

I'm glad this might mean something to you because it is greek to me :). Thanks again Bob.

They indicate levels about what your modems is hearing and talking to the headend and how good/noisy the signal.

Signal to noise is indication of quality of the signal.

It looks like your headhend is SCREAMING at you :( and you are talking at a normal level to the headhend. :)

Values from my setup.

Motorola Surboard SB5120 QAM 256 (Working range, my norm) Down Power -4 dBmV (-10 to +10 dBmV, -1 dBmV) SNR 37 dB (higher than 33 dB, 37 dB) Up Power 43 dBmV (30 to 55 dBmV, 44 dBmV)

IMHO, 9 dBmV Downstream is perfectly acceptable. The rest of the levels look good to me, too.

I would continue to check the levels periodically to see if they fluctuate. It's possible they're intermittently moving outside of the working range for short periods.

I had a similar problem, losing connectivity. Mine was not related to large downloads though. I was convinced that the problem was between the ISP's distribution point and my connection at the pole. We would experience intermittent dropouts throughout the day. I used a program called Link Monitor, available for free from

logs:http://192.168.100.1/logs.htm> >

I had been expecting to see the remnants of one of those re-boots in the modem log and the log contents are not consistent with the problem you're describing. Since I would expect that you would be reporting all this fairly close after one of the events, I don't expect to see a two week old entry in the log.

My preliminary conclusion is that your modem connection is working just fine, that's one reason your lights remain normal and these "disconnects" have nothing to do with your modem connection.

Charter must have some more serious problems or the newsgroup service you use might be the problem.

Bob

logs:http://192.168.100.1/logs.htm>

something:http://192.168.100.1/signal.htm>

Thanks for all the feedback, I really appreciate the help. Just for peace of mind I ordered a new modem yesterday and it should be in today. One thing I noticed is that if i throttle the speed down to about 1MBs in my newsgroup software it runs perfect right at 1MBs without any problems. When i take the speed limiter off my download speed fluctuates between 100k and a little over 1MBs and will then drop completely as described in my original post. I have 10Mbs download speed and its been a while since its been working right but i think i recall getting near 2MBs download speeds. I have tried using 3 diffrent usenet service providers and I get the same problem with all(charter limits my connection speed through their NNTP servers.) I have an easynews.com account and they have a web interface to browse their binaries and i get the same issues with that also. I live in a Condo complex with about 100 units and im not sure how the cable company drops their cable to my unit but from what im hearing above it sounds like that might be the problem. Either that or this is Karma coming back to get me ;). I will check out the things you guys mentioned above and hopefully get some answers from charter. Ill let you know what i come up with. Thanks again everyone.

Your terminology is a bit confusing because you are saying 1 MBs (1 MegaBytes per second), but the context is of 1 Mbs (1 Megabits per second.

If your download cap speed at Charter is 10 Mbs, then 1 Mbs is pretty bad

It should be up close to 10 Mega bits per second. There is a problem with Charter.

If you're paying for 10, then you should be getting 10.

Charter is the obviously the problem.

Good luck.

I was using my download speed as it is represented when i download. When downloading from my newsgroup browser it lists it in Mega Bytes/ s . My download speed from charter is 10 Mega Bits/s so my download speed in my newsgroup software is roughly at 8Mb/s peak (although if my speed limiter is off it rarely touches that speed). Looking back i guess saying i WAS getting 2 MB/s was a little over what i could possibly get with a 10Mb/s download from charter. I know it was more than the 1MB/s max im getting now though. Im gonna stop talking now because I am beginning to confuse myself :).

logs:http://192.168.100.1/logs.htm>>

something:http://192.168.100.1/signal.htm>>

We used to call it "shotgunning" when an element is replaced without evidence of failure. In other words, without fully troubleshooting the issue. In this case, I didn't see any indication of a bad modem, but you may get lucky.

You said you already replaced the router, (more shotgunning?), but your issue does remind me that certain older Linksys routers were known to stop passing traffic when subjected to sustained heavy traffic loads. One cause was an improper MTU setting, which I recall could be fixed by manually changing the MTU setting or upgrading the firmware. The other cause that comes to mind was a batch of weak Linksys power supplies.

You also said you replaced your NIC, which was even more shotgunning since you didn't mention whether you checked connectivity during an outage period.

Next time you lose Internet connectivity, see if you can ping your router. If you can, your NIC and Cat5 cable are good. See if you can ping your cable modem. If you can, the Cat5 cable between the router and modem are good, and the LAN side of the cable modem is probably good. See if you can ping your default gateway (get its IP from your router's Admin page). If you can, your modem is good. Alternatively or in addition, ping your assigned DNS servers to help verify connectivity. Check your modem's signal levels during an outage and compare them to the levels you posted above.

Bottom line, attack issues such as this as logically as possible. Resist the urge to replace something unless you have evidence that it's part of the problem. So far, you probably have a perfectly good spare modem, router, NIC, and possibly cables in your parts box.

For the most part I was using either parts I already had or parts I wanted but needed an excuse to feel good about buying them. This in my mind justified that urge. As far as this modem my girlfriend is leasing hers and i found a good deal on the D-Link DCM 202 so i told her she could have my Motorola and save some bucks. Thanks for the pinging tips, that all makes sense and I wish I had talked to you a couple months ago about this. After this i guess I better post "How to resist impulse buying" on the psychology groups :).