Connection dropping constantly [Archive] - Glock Talk

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ThinkOfTheChildren
11-18-2005, 14:07
I just got Comcast high-speed cable hooked up here about ten days ago. At first, everything was great: I was even getting speeds faster than advertised. Then after a day or two the speeds came down to what they "should" be based on my package. Now, in the last 48 hours, my connection has decided to go ape. I'm hooked up on a Motorola SB5101 and it just drops me cold in the middle of doing things on the net. One second it's online, and then suddenly the "online" light on the modem turns off and other lights start blinking. It looks like it tries to correct itself but in the end I have to physically unplug the modem and then plug it back in to get it online again. I'm not using a router or anything else: it's just that the modem is kicking out on me.

I Googled around and apparently this isn't an uncommon problem. The problem, however, is that nothing I've read so far explains it. Some have problems with this same modem on different cable companies, but then some others who have different modems have the same problem with Comcast. Some suggestions have been made about limiting traffic so as not to "overload" the modem (which is annoying since I pay for high-speed internet for a reason), and then many suggestions have been made about firmware, software, routers, etc etc etc. No one has a straight answer and none of the suggestions I've seen pan out. I've even read bs about or blowing a fan on the cable modem to keep it cool and to not have your cell phone near the cable modem .

DOES ANYONE HAVE ANY IDEA PLEASE? I've been messing with this thing all day and reset it probably around 20 times. I would call Comcast for support but I'm about to head out for a night shift of work. (I try to avoid calling support until I've exhausted all self-help options and am ready to sit on hold and talk to someone for a loooong time who will tell me things I've already tried.)

Who else has (or had) problems with dropped connections on cable modems? Did you find a solution? I will call Comcast as soon as is possible but if I don't get a straight answer about this from them (or whomever) I'm going to have to switch over to DSL (which never gave me any problems in the past).

I'm about ready to throw this damn modem out the window.

JCM298
11-18-2005, 15:55
I have Cox Cable. Every now and then, the system goes nuts. After I check the obvious causes, I call Cox. They have been very helpful. Comcast should be able to guide you,

John

funbob
11-18-2005, 21:06
You're almost certainly having a problem with your upstream power levels. Check your signal levels by clicking on http://192.168.100.1/signal.html and report back what the values on that page are.

ThinkOfTheChildren
11-19-2005, 00:02
Downstream Value
Frequency 565778200 Hz
Signal To Noise Ratio 39.8 dB
Power Level 12.2 dBmV


Upstream Value
Channel ID 5
Frequency 26000000 Hz
Power 26.0 dBmV


I appreciate any help you can offer. It just now took almost an hour for the modem to get online (progress lights kept almost getting to online but would then start over again).

JMag
11-19-2005, 00:29
Looking at your power level (I am not an expert here though) I bet you need to ramp (read amp) up your signal. Circuit City or your cable company can help you out for around $50.

Good luck!

ThinkOfTheChildren
11-19-2005, 10:01
Thanks, JMag. If it comes to spending just one penny more, I'll simply switch to DSL. I'm not going to spend extra money to fix a service that should be working properly as delivered.

I'm on the phone with Comcast right now (been on hold for over 15 minutes) and I'm not sure how much longer I can sit here. I have things I need to do today.

I also fired an email off to them.

This morning my modem hasn't reset on me but all internet usage has been sloooow. I suspect if I tried to load the connection at all, it would reset. That seems to be the surest way to get it to reset (though it still resets on its own for no reason at times).

JMag
11-19-2005, 11:53
Thinkofthechildren,

As you may know,the more cable outlets you have in your house, the more apt you are to need an amp. I learned that a few years ago as I had a poor signal.

I think once you get it squared you will be MUCH happier with cable broadband than any DSL from any supplier.

Best.

funbob
11-19-2005, 19:49
Originally posted by ThinkOfTheChildren
Downstream Value
Frequency 565778200 Hz
Signal To Noise Ratio 39.8 dB
Power Level 12.2 dBmV


Upstream Value
Channel ID 5
Frequency 26000000 Hz
Power 26.0 dBmV


Your upstream power level is excellent, it's actually your your downstream power level that may be causing your problems. The SNR is good, but the power level is on the high side. 15dB is the max allowed in the DOCSIS spec, but in practical use, 12dB is a more realistic value and you're at 12.2. The ideal number would be below 8. Are any splitters in use on the cable modem line? Is this a house or apartment? What type of wiring is in use? There could be lots of reasons for this problem.

JMag
11-19-2005, 21:51
Funbob, thanks for clarifying that for me, too. My downstream power level is 1dB, upstream is 41dB, BTW, SNR is 35dB. Am I good to go?

I have a friend in the 'hood who had to have a section of cable replaced between the outside feed and the house as it was compromised in some way.

funbob
11-20-2005, 11:44
Originally posted by JMag
Funbob, thanks for clarifying that for me, too. My downstream power level is 1dB, upstream is 41dB, BTW, SNR is 35dB. Am I good to go?

I have a friend in the 'hood who had to have a section of cable replaced between the outside feed and the house as it was compromised in some way.

Yes, those are good signal levels. Downstream power should be as close to 0dB as possible, the SNR should be over 30, and upstream power should be under 50dB, the lower the better. The most common source of poor signal levels is cable damage. Even a small nick will compromise the line.

JMag
11-20-2005, 19:45
Thanks, funbod.

ThinkOfTheChildren
11-22-2005, 14:30
Sorry for taking a bit to get back to this.

I'm in a condo building that has new wiring (the condos were just built out of an old building). I have three rooms, each with a jack. One room has a TV on the jack, one room has the computer, and the other room is untouched. There are no splitters in use anywhere.

I called Comcast but when I did so the problem wasn't happening right that second. The tech on the phone basically said, "Well if it's not happening now, I can't help you. Call me when it goes bad again." I kept him on the line as long as possible to talk about my readings and why I would have gotten all those drops. He kept giving me different answers... told me maybe some work was being done in the neighborhood, or maybe I should check my wires, etc. Even said I should scan for spyware and all the usuals. Basically, he didn't give any straight answers but was nice.

I've been problem free since I last posted in here. I'm hoping it stays that way. My current readings are:

Downstream Value
Frequency 565778200 Hz
Signal To Noise Ratio 39.4 dB
Power Level 11.2 dBmV

Upstream Value
Channel ID 5
Frequency 26000000 Hz
Power 26.5 dBmV

When I talked to the tech on the phone, my Downstream power level was around 9, so it would seem that my reading is fluctuating a number of points.

Like I said, I haven't had any problems for a short while but should I do something to bring the downstream power down somewhat?

Str8shootr
11-28-2005, 13:19
My case:

I too am a Comcast subscriber. Live alone in an apartment, 2 TV's one laptop cable connection via a cable modem and wireless router. I too was constantly resetting my cable modem and wireless router. My modem was used from someone's office, the router was new Lynksys.

I figured my modem was bad so went and bought a new Lynksys modem. While configuring the new modem with a Comcast tecky (very polite and professional) the tech noticed I had a lot of interference up line from my connection. I told him that my signal was weak on my computer when in the living room, but excellent in my bedroom twenty feet away. That is why I replaced the modem. He set up a maintenance check a few days later.

After adjusting the outside box and fixing the "leaks" of signal in my apartment (he basically replaced all my cables in my apartment) told me he had taken me from 70% up to 98.5%. Problem is, the modem doesn't have to be reset anymore, but my signal strength is still low in the living room and excellent in the bedroom.

Can someone point me in a direction to solve MY problem?

Thanks

funbob
11-28-2005, 23:14
I'm confused when you refer to a weak signal. Are you referring to the strength of your wifi connection as you move about in the house? That has nothing to do with your cable modem.

Str8shootr
11-29-2005, 04:35
When I click on my wireless connection icon, it tells me the signal strength, low in Living room, high in bedroom which is where I have my modem and router.

funbob
11-29-2005, 15:32
That's a problem with your router. Some things you can try to improve the situation include moving the router to an elevated position. Upstairs if you have a 2 story apartment otherwise on top of a bookshelf would be good. Make sure the antennas are pointing straight up on the router. Tilting them in any direction degrades the signal. Is the router near any large metallic mass or other electronic devices? Try moving it to a more suitable spot if it is. Are there any potential interference causing devices in the house? 2.4Ghz wireless phones, cheap microwaves, and bluetooth devices are common culprits. There could also be nearby wireless networks causing problems. You can try switching your channel to one that is not being used by other nearby networks. Your router configuration screen can be accessed at http://192.168.1.1/ . Does your laptop have integrated wifi or are you using an external wifi device? Sometimes, the integrated wifi in laptops isn't the greatest and you can greatly improve the situation by purchases an external wifi device. There are also high gain antennas you can purchase for your router that will provide several dB's of gain.

Str8shootr
11-30-2005, 10:59
Thanks funbob!

I will try some of those things you mentioned and see if it helps.......thank God for Glocktalk....LOL:cool: