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Fed up - constant intermittent outages and very slow speeds

Donstim
Frequent Visitor

Fed up - constant intermittent outages and very slow speeds

For at least the last 3 weeks, we have had intermittent short term outages and very slow internet speeds. Today has been the worst. We get pings from our home security tablet that service has been lost about 5-10 times an hour. It often takes several attempts to load a web page, getting "no internet" and/or DNS not found errors each time, until it finally goes through. Same issues with TV service. I've checked with our neighbors and they are having the same issues.

 

Yet, I cannot contact technical support -- neither chat nor phone support allows me past the redundant automated trouble shooter. I've checked and tightened cables and had the mode and gateway rebooted multiple times with no improvement. I am not getting anywhere near the service I am paying for.

Donstim
Frequent Visitor

Re: Fed up - constant intermittent outages and very slow speeds

From all the posts, it looks like this is a common issue.  Would be nice if Xfinity/Comcast would at least fess up and admit to the problem.

EG
Expert

Re: Fed up - constant intermittent outages and very slow speeds

Start here;


https://forums.xfinity.com/t5/Your-Home-Network/Internet-Troubleshooting-Tips/m-p/3310447#M316652

 



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Donstim
Frequent Visitor

Re: Fed up - constant intermittent outages and very slow speeds

Thanks, but I am well aware of what is provided as an FAQ in many places. Been there done that. The problem is not on my end.
EG
Expert

Re: Fed up - constant intermittent outages and very slow speeds

Then good luck with it ! 🙂



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Donstim
Frequent Visitor

Re: Fed up - constant intermittent outages and very slow speeds

Ok, here is further info on my modem power levels, modem log, and speedtest results. As luck would have it, everything is working peachy this morning - highest download speeds I've seen in a while...

NETGEAR Modem CM1100 (1).png
NETGEAR Modem CM1100 (2).png
NETGEAR Modem CM1100 (3).png
NETGEAR Modem CM1100.png
Results   Speedtest by Ookla.png
EG
Expert

Re: Fed up - constant intermittent outages and very slow speeds

Well you do have a signal / connection quality problem. The upstream power is too high and it may be intermittently fluctuating even higher to out of spec levels.  The downstream power is on the low / weak side as well. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, 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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Donstim
Frequent Visitor

Re: Fed up - constant intermittent outages and very slow speeds

No user-installed splitters here. Only a Comcast/Xfinity installed amplifier/splitter that supplies cable connections to 8 different locations in our house. It's fairly new -- was installed about a year ago when we switched to Comcast Home Security.

 

In what range should the signal levels be?

 

Kind of interesting that our neighbor across the street is experiencing the same issues (with completely different equipment).

 

The problem is I don't know how to get a tech here.

EG
Expert

Re: Fed up - constant intermittent outages and very slow speeds


@Donstim wrote:

 

In what range should the signal levels be?


Specification      Min             Max
Downstream Power Level    
Cable Modems -10dBmV +10dBmV
Gateways and EMTAs -7dBmV +7dBmV
Downstream Signal to Noise Ratio 35dB -
Upstream Power Level +35dBmV +50dBmV
Upstream Signal to Noise Ratio 31dB -
Upstream Receive Power -2dBmV +2dBmV


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Donstim
Frequent Visitor

Re: Fed up - constant intermittent outages and very slow speeds

Yeah, I saw that. Based on that, I thought the downstream power and SNR levels looked fine. Upstream definitely high. I don't know what causes such a difference though. Wouldn't wiring/splitter issues affect both equally?

EG
Expert

Re: Fed up - constant intermittent outages and very slow speeds


@Donstim wrote:

Yeah, I saw that. Based on that, I thought the downstream power and SNR levels looked fine. Upstream definitely high. I don't know what causes such a difference though. Wouldn't wiring/splitter issues affect both equally?


Typically yes. I stated that the downstream power was on the "low / weak side, not that it was out of spec.



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Donstim
Frequent Visitor

Re: Fed up - constant intermittent outages and very slow speeds

Well, over the last few days, my cable service has returned to normal -- normal speeds, no disconnects/intermittency/etc. I don't know what, if anything, may have been done (nothing was done on my end and modem stats still read the same), but thank you!