Loosing Internet Connection (Cable Internet)

West996

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Sep 24, 2012
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10,510
Hey Everyone,

I am really hoping someone can help me with this because apparently my ISP can't..

I live in Canada and my ISP is called Cogeco Cable. I am running a Cable modem. I have tried running the connection through a router as well as being connected directly to the modem.

I am running a wired connection.

I seem to loose internet connection at random. Sometimes a few times a week, sometimes multiple times a day. It stays down anywhere from 8 to 10 hours, and sometimes I can get it back up and going in 30 to 45 minutes.

I get it back up by resetting the modem either by pressing the button in the back or by disconnecting the power. I wait anywhere from 10 seconds to a few minutes before I reconnect the modem, it doesn't seem to make a difference.

Sometimes the modem with continually reset itself. I can sit there watching it, it will connect stay connected for about 30 seconds, and then reset all by itself and reconnects. It has done this upwards for 5 or 6 times in a row before it gains a stable connection.

My ISP has sent 4 service people over since they installed it 3 months ago. It has never worked consistently. Tomorrow they are sending the 5th.

So far they have :

Replaced the modem

Checked and replaced some of the connections that are inside my house coming from the outside.

Set up a temporary line running straight from the cable box at the street, up the lamp post and into my house.

I have also taken the actual cable cord coming from the wall into the modem and replaced it with one that we were using for the TV that has always worked.

None of this seems to make a difference. I suspected someone had cloned my MAC address but I have check my usage and it has not gone up.

I also have my home phone service through the cable company as well. When my internet goes down, my phone goes down too. Although recently I noticed something strange. Sometimes I will have internet service, but not phone service. Is it possible my phone, or my phone line is sending feedback, or some how interfering with my internet connection?

I am very discouraged and really at a loss of what to do. I can't imagine what this 5th guy coming tomorrow is going to do differently.

Any suggestions are most appreciated. Thank you.
 
Solution
Downstream is excellent. Upstream however is way too high. An Arris should be in the mid 40's. You've got a cable side problem there. Modem has to shout to be heard. How many splitters between the modem and the point that the drop enters the house? (Ideally none, but 1 is OK)
Most likely a signal problem on the cable side. The modem will reset if it can't communicate with the headend. Most likely the problem is with upstream and the transmitter on the modem is maxed out.

If you have a Motorola modem surf to "http://192.168.100.1". This is the modem's internal web server. Once there choose the "signal" tab. On a Motorola modem you want to see a downstream level somewhere near "0" and an upstream level in the mid 30's. If you see upstream in the high 40's to low 50's (modem maxes as 54) then the problem is cable side. Same for downstream levels if significantly lower than "0".
 

West996

Honorable
Sep 24, 2012
8
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10,510
I have an Arris router, same IP worked though.

Downstream
Freq/Power: 513.000 MHz 4 dBmV
Signal to Noise Ratio: 39 dB
Modulation: QAM256
Upstream
Freq/Power: 35.296 MHz 55 dBmV
Channel Type: Mixed (TDMA and ATDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM16

That is what I got though I'm not to sure what I am looking at. How does that look to you?
 
Downstream is excellent. Upstream however is way too high. An Arris should be in the mid 40's. You've got a cable side problem there. Modem has to shout to be heard. How many splitters between the modem and the point that the drop enters the house? (Ideally none, but 1 is OK)
 
Solution

West996

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Sep 24, 2012
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10,510
Well it is hard for me to tell, as you can tell I'm not very savvy when it comes to this. In my fuse box though (that is where it is all housed), I see two cable splitters. One is a tripple, and one is a double.

It is hard for me to tell which goes where, which ones I need and which ones I can eliminate.
 
I have a feeling the signal is going through both splitters to get to the modem. That's quite a drop, unless the 2-way is a DC splitter. Best bet is to get the cable company to to a thorough test on the system, and if you can get the tech to do it, draw out your setup for future reference.

It's definitely on the cable side though.
 

West996

Honorable
Sep 24, 2012
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10,510
I posted a picture of the set up on my twitter. I didn't know how to post this on the forum. I don't know if this will tell you anything.

https://twitter.com/West996/status/250364014205472768/photo/1

Thanks a lot for the help though. If I can point this guy in the right direction maybe I can actually get this fixed.

Went down again just now. I unplugged what I think went into the cable outlet into the wall and plugged the modem directly into the splitter.

Downstream
Freq/Power: 519.000 MHz 5 dBmV
Signal to Noise Ratio: 39 dB
Modulation: QAM256
Upstream
Freq/Power: 28.704 MHz 46 dBmV
Channel Type: DOCSIS 2.0 (ATDMA)
Symbol Rate: 2560 kSym/sec
Modulation: QAM64

Already have a lower Upstream and that is just eliminating the wall outlet. Is it possible the outlet is crappy?

Unplugging one splitter from the next brings no change to the above stats, but I also didn't restart the modem to check that because I'm so scared that every time the modem restarts it won't come back up.
 


Picture's not accessible.

I think you may have found it. A 9dB drop is significant (almost 10x change) and puts the upstream signal right about where it should be for that modem.
 

West996

Honorable
Sep 24, 2012
8
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10,510
Can you see my profile picture? I also uploaded it there.

I'll still mention it to the cable guy, he is coming tomorrow, but I think I may have found it. Like ex_bubblehead said, I noticed a change in the upstream db right away.

After I disconnected the the first splitter from the second splitter I didn't notice any change at all. The cable coming from the house comes into the first splitter which seems to be connected to the wall jack that the modem was plugged into. So it doesn't go through the second splitter to get to the modem, that second splitter goes to the TV's.

 

West996

Honorable
Sep 24, 2012
8
0
10,510
So just as an update, my ISP service guy just left. He saw that I had bypassed the cable jack, I showed him the difference in the upstream readings. When I showed him the first reading his said, "Oh yeah, that is way too high.", then I showed him the new reading with the jack bypassed, and told him everything seemed to be fine.

So it looks like I should have just come to this forum in the first place.

4 ISP service men came to my house and could not find the problem, I post on a single forum and my first response is the right answer.

Can't thank you enough.