Arris SB8200 signals

Thank you @EG . 

We only have internet at our townhouse.  No TV or phone, so no other equipment and no splitters within the townhouse.   As far as I know, there are not any splitters between the tap and what comes into the basement from the Comcast cable box on the outside of the town house.  When we were first connected, we did not have a dedicated drop from the pedestal to the cable box on the outside of the house, so they put us on a splitter to share with the unit next to us until the drop was installed.   When the drop was installed, they said they took our connection off the splitter.  This all happened last April, but due to having to keep our distance, I did not go out and look in the cable box to verify that the splitter had been removed.   We never had an issue during the few weeks were shared a drop and until today, never an issue while on our own drop.   The townhouse is two years old.  All Internal Coax is  RG6.  The cable modem is currently in the family room, so there are two  F connector splices between the cable modem the outside box; one in the utility room and one in the wall plate in the family room.   

We do have a tech coming tomorrow morning. 

Bear in mind that if the premises facing techs can not find or fix a problem at your premises, 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 with it !

---

@EG wrote:

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

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.

---

@EG   

BTW... what are the ideal Power and SNR levels that we should hope to see?   We are definitely seeing random disconnects, and the speeds I've measured when we do have a connection range from  2 - 15 Mbps  down and 4 - 5 Mbps up.    My VoIP phone reboots itself every time the internet is lost for 10-30 seconds or so, and I have been watching it reboot every two or three minutes.   Makes comms with our HQ offices impossible. 

I also meant to post the latest event log from the Arris SB8200.  I certainly don't understand the events. 

Date Time Event ID Event Level Description

From the pinned Troubleshooting Tips topic at the top of this board;

Specification      Min             Max

Nope. The downstream power levels and the SNR's are still out of spec. More work is needed.

The Xfinity techician visited this morning.  He first checked signals at the network box and said the signals/power levers from the tap looked good. 

He was able to see the power and SNR levels for the modem and could see those levers were not good.  He warned that it could be that the modem was going bad, but said he would check the terminations.   He noted that the coax terminations were not done very well.   These terminatinos were not done by Xfinity.  They never had a chance to come in the home last spring since on the very day of our install, the technicians in our area had been ordered to no longer enter homes due to COVID-19 risks.  Therefore, the terminations were done by third party network installer who was willing to enter homes.  Since everything worked fine once those original terminations were done, we trusted the terminations had been done right.   

Here is a photo showing a normal termination on the left, the builder's electrical contractor's termination at a wall plate 2nd from left, and the third party network installer's two terminations on the right.   

In case this photo doesn't show in this forum thread, here is an imgur link:
One good - three bad  - Imgur

The tech that visited this morning said that over time with temp changes or any vibrations, like a furnace in next to the wall were all the cables terminate, could cause a barely working connection to stop working as well as it once had.  The tech also checked the wall jack termination, which had been done by the builder's electrical contractor. That termination was also not correctly "seated".  

After the Xfinity tech re-terminated all the connections and hooked up the cable modem the internet returned to normal speeds and stopped dropping connections. I think these power levels and SNR values might be more normal now: 

@EG 
How do I convince Xfinity that more work is needed?

Also, since Xfinity left, I was able to reach 192.168.100.1  just once.   I can no longer navigate to my SB8200 and just get a message that says  192.168.100.1 refused to connect. 

Any tech worth their salt can obviously see that the numbers are off. Show them this thread.