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Connectivity issues, internet drops randomly

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New Poster

Connectivity issues, internet drops randomly

Hello, my internet used to drop a few times a month, and sometimes would not come up for days. It seemed to stop for probably 4-6 months, and in that time I got a new modem just because I found a good deal in case it was the issue. It is back to doing it today. At random, it suddenly goes out, and it will blink the "sending" light over and over, but will not get past it. I can usually just power cycle the modem and it comes back on, but it is a constant thing. Comcast came out prior and said we had noise in our wires, and gave us new ends on all cables and it seemed to fix the noise that we didn't notice. I've been told our downstream levels are low. My prior and current modem is the Surfboard SBG6580. Any ideas will help, thank you.

Accepted Solution

Re: Connectivity issues, internet drops randomly

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The downstream power and the SNR's are o/k. The upstream power is too high and may be intermittently fluctuating even higher out of spec. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.


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Connection Expert

Re: Connectivity issues, internet drops randomly

The downstream power and the SNR's are o/k. The upstream power is too high and may be intermittently fluctuating even higher out of spec. That can cause random disconnects, spontaneous re-booting of the modem, and speed and latency problems.

In a self troubleshooting effort to try to obtain better connectivity / more wiggle room, check to see if there are there any excess/unneeded coax cable splitters in the line leading to the modem that can be eliminated/re-configured. Any splitters that remain should be high quality and cable rated for 5-1002 MHz, bi-directional, and no gold colored garbage types like GE, RadioShack, RCA, Philips, Leviton, Magnavox, and Rocketfish from big box stores like Home Depot, Lowes, Target, Wal-Mart etc. Splitters should be swapped with known to be good / new ones to test

If there aren't any unneeded splitters that can be eliminated and if your coax wiring setup can't be reconfigured so that there is a single two way splitter connected directly off of the drop from the street/pole with one port feeding the modem and the other port feeding the rest of the house/equipment with additional splits as needed, and you've checked all the wiring and fittings for integrity and tightness and refresh them by taking them apart then check for and clean off any corrosion / oxidation on the center wire and put them back together again, then perhaps it's best to book a tech visit to investigate and correct.





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New Poster

Re: Connectivity issues, internet drops randomly

I do believe I have a pretty cheap splitter, but I do not know where to buy a decent one, let alone an 8 way splitter that is needed for my house. Do you know of a website or another place where I can purchase a good 8 way splitter? Also, could it still be the splitter causing the problem if I've had the same splitter for the entirety of this ordeal, where it didn't drop for 4-6 months and then suddenly started again? Thank you for the information I appreciate it.

Connection Expert

Re: Connectivity issues, internet drops randomly

Please re-read the first sentence of the third paragraph. Ideally you want to hang the modem off of one the ports of a two-way splitter and have everything else connected to the other port with additional splits as needed.




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New Poster

Re: Connectivity issues, internet drops randomly

Ah I'm sorry I see now. Thank you I will do that.

Connection Expert

Re: Connectivity issues, internet drops randomly

No worries. Good luck with it ! Post back with how things turn out.




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New Poster

Re: Connectivity issues, internet drops randomly

I've actually did what you said, and now I'm getting way better numbers. Sad thing is, is that my internet keeps going out still. If I remove the coxial cable and put it back in the internet comes right back on, and if that doesn't work, a few power cycles will make it work. 

connection2.png
Connection Expert

Re: Connectivity issues, internet drops randomly

Post what the figures are now. <<<<<<< Disregard. Looks good now !

 

Is the "sending" light still going off and blinking when this happens now ?




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New Poster

Re: Connectivity issues, internet drops randomly

Here is after the new splitter is added exactly as you said.

connection2.png
New Poster

Re: Connectivity issues, internet drops randomly

Yes, the "sending" light is still hanging after the internet goes out and the modem resets itself. Let it be known that it will say the internet is off on my pc, but the modem stays lit like it's working for a minute or two before it resets.

Connection Expert

Re: Connectivity issues, internet drops randomly

Hmmmm. There are three additional signal stats that can cause communication problems between the modem and the system which can't be read by the modem that can cause communication problems between the modem and the system. They can only be read from their end by them polling the CMTS (Cable Modem Termination System) at the local headend facility.

They are the "Upstream Rx Power" (Upstream Receive Power Level), the "Upstream SNR Ch." (Upstream Signal To Noise Ratio), and the "Upstream ICFR" (In Channel Frequency Response). These are as equally important in diagnosing connectivity issues as are the modem's stats.

You can call in and ask what these figures are. The Upstream Receive Power Level should fall within the range of -2dB to +2dB with 0dB being in the middle and perfect.

The Upstream SNR should be least 31dB, and the higher it is the better.

The ICFR should be no higher than 2 dB.

You could have an intermittent noise ingress issue in only the upstream channel(s) / return path only somewhere.

They will be able to see whether or not everything is in the green zone.




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New Poster

Re: Connectivity issues, internet drops randomly

Will any of their reps be able to tell me those numbers, or will I have to find that out from someone that knows more about these technical issues? Thanks. I'll give them a call in a bit.

Connection Expert

Re: Connectivity issues, internet drops randomly

You may have problems with the tier 1 reps. If so, for a tier 2 rep or a supervisor.




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New Poster

Re: Connectivity issues, internet drops randomly

Alright, thank you for all of the help I seriously appreciate it.

Connection Expert

Re: Connectivity issues, internet drops randomly

Quite welcome ! Smiley Happy




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New Poster

Re: Connectivity issues, internet drops randomly

I didn't call comcast since my internet has been holding up, but after 1 hour and 45 minutes, the numbers are slowly going back up. Also, I'm getting correcteds and uncorrectables at this time. I think it's going to go out soon by looking at these numbers. Could it still be what you mentioned? If so, I'll call comcast if it goes out.

 

EDIT: Just as I was going to send these numbers, my internet went out again. A quick power cycle brought it back up. Here's the numbers as it went down.

connection3.png
New Poster

Re: Connectivity issues, internet drops randomly

People said this modem has problems with connectivity issues, but it's weird that it was working for 6 months with not even a single drop, and now today it's dropped every hour.

Connection Expert

Re: Connectivity issues, internet drops randomly

Could be. Or it could be a malfunctioning modem.




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