Intermittent performance problems

If there is nothing that can be done to improve the connection, then as stated,  you might want to get a tech out to investigate this issue.

Bear in mind that if the premises facing techs can not find or fix a problem at your home, it is they who are responsible for escalating it to their line / network / maintenance dept. techs. The problem may lie beyond your home in the local neighborhood infrastructure somewhere but it is their S.O.P. to start at the home.

Good luck !

Are these WiFi connections ? If so, for a test, does a computer / device that is hardwired directly to the 8300 with an ethernet cable have the same problem ?

With this test, we are trying to isolate this from being either a WiFi-only problem or a problem with the general connection to the Comcast system which would of course affect both. It's a good first step of troubleshooting before proceeding any further.

Good call, these tests were on wifi. I do have a cabled system plugged in, though I'm not experiencing any performance problems now. I just ran the speedtest though to get a baseline, confirmed to be at 100Mbps right now.

Skylar

What do the modem's signal stats look like ? 

Please post the *Downstream Power Level*, the *Upstream Power Level*, and the *SNR* (Signal to Noise Ratio) numbers.

The downstream power is too low /out of spec. And some of the SNR's are on the low side. That can cause random disconnects, spontaneous re-booting of the modem, speed, packet loss, latency problems, and the un-bonding of channels.

In an 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 5-1000 MHz, bi-directional, and no gold colored garbage from Radio Shack, Home Depot, Target, etc. Splitters should be swapped with known to be good / new ones to test.

Also check the coax cable for any damage such as cuts, nicks, kinks, sharp bends, etc.

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.

Good luck with it !

It's the Comcast plant / engineering specs that matter ! These are from the pinned "Troubleshooting Tips" post at the top of this board;

I just wanted to post an update, and fortunately a happy resolution. As you suspected, the problem was the cable between the modem and the wall. Moral of the story is, don't trust the 15 year old cable that came out of a random box after moving. New cable is much better with SNR and power level numbers all within spec.

Skylar

@skylar42 

Thanks for circling back ! For curiosity, would you please post what the stats look like now ?

@skylar42 

More needs to be done.... Most of the downstreams are still too low / out of spec. There's no wiggle room. You may want to get a tech out to investigate / correct the problem. Good luck !

Yeah, still not perfect though performance is much more consistent/stable. If it gives us more trouble we'll get a tech out though. Thanks for the help and suggestions!

Skylar

Hope things hold up for you ! Good luck !