Thanks for the updates. Can you tell us what you've been experiencing today connectivity-wise, outside of the modem logs?
a lot of things can recover from packet loss as packets are just resent .. streaming video tends to buffer so a couple seconds might not be a problem. I guess it just depends.
9/8/2019 7:26:54 AM Log Start
Failure Start Length
9/8/2019 7:54:44 AM 0:00:01
9/8/2019 10:15:28 AM 0:09:07
9/8/2019 11:39:12 AM 0:00:01
9/8/2019 11:47:20 AM 0:00:08
9/8/2019 11:49:54 AM 0:00:14
9/8/2019 12:30:02 PM 0:00:01
9/8/2019 12:40:55 PM 0:00:12
9/8/2019 1:15:35 PM 0:00:08
If I may ask a couple questions of you .. Is what my modem logs reflect normal system operations for xfinity?
Is the modem you installed next to mine today reflecting the same issues?
Lets have this communication be a two way street.
We would love to take a closer look at your logs and the health report records we have to better help pinpoint the cause of your connection issues. Can you please send a private message to us (Comcast_Support) with your first and last name so we can assist you further?
Update - Comcast replaced the booster on the pole and remotely reset my modem and things are good so far (16 hours). I have a couple correctables but nothing in the logs and more importantly even the 1 second outages seem to have gone away . I will cross my fingers once again and hope this solves the problem.
Glad to hear about the additional changes/update in attempt to rectify the issue. We are hoping for the best as well. We will keep this open for a while longer, just in case you need us. However after the changes, you should experience more continued stability.
I need another day or two before I can safetly say the problem has been fixed. I know Comcast wants to close out the BBB case and I am sure the forum admins want to lock this thread but patience please .. its been weeks with this issue give it a day or two before you check the solved box ;-) .
Sure. We completely understand that. No problem. We will be around.
Your screenshot makes us happy too. That is exciting!
Hello again, jrose78! We appreciate your update and are sad to see you are still having connectivity issues. We would like to work directly with you to take a closer look so we can get this corrected quickly. Please send us a private message to Comcast_Support so we can assist further.
I have messaged you directly already (read first page) . If you would like to fix this problem private message me with a possible fix or if you need additional information. Issue still continues, see images below.
We have not received any PM's to our Comcast_Support inbox. If you would like assistance with this issue, please send a PM to Comcast_Support.
then how is this post possible? That post is on page one but even after I asked you to read it you didn't. Is that person a comcast employee?
Any user with the " Official Comcast Employee" banner is an official employee. We ask that you message us at Comcast_Support so that you can receive timely support from our team. However, if you are messaging an individual user you may not receive a response if they are away for the weekend, on vacation, or no longer with our team.
So if someone goes on vacation they would hand off any open cases they are working on I would think? If you fire someone them maybe someone can review any open cases they had and follow up? Honestly this whole back and forth is not productive. Maybe you can just ask if I tried unplugging and plugging my modem back in again and we can move on to level 2 support?
My uploaded screen captures where removed a couple posts up .... I uploaded them again since I didn't get any notification they where removed for a reason
Hi jrose78, thank you for your reply and we would like to help review this further on this side and submit a ticket to our tier 2 team or schedule a technician accordingly. If you are still needing assistance please send a private message to Comcast_Support with your full name and account number and we can help further. Unfortunately I am unable to see your original private message you mentioned earlier in this thread.
Update: Just to recap I have tried two mb8600 cable modems and both would lose internet on and off. I have now switched to using comcasts modem xb something and I have not had outages for 24hrs. Below is a screenshot of some uncorretables but not many and no outages detected. I find it interesting that the comcast modem is dealing better with issues on the network than both the mb8600 I had although time will tell. I have ordered a sb8200 from Amazon and will try that out when it arrives because I want to use my own modem. I wonder if manufacturers are giving the cable companies better chipsets than what they sell to the general market. I figure in this area most people rent comcast cable modems and I wonder if comcast when judging if there is a network issues notices none of there rented modem have problems. For example they say well no other cable modem in that area are having problems kinda thing. I imagine if the network is noise free that the mb8600 would work ... anyway just a theory and its only been 24hrs .
Bottom number is uncorrects:
My new modem is arriving today (sb8200) and is replacing the mb8600. I did a little research and they both use the same chipset Broadcom 3390 so It will be interesting to see if the new modem has issues like the mb8600.
I was just reading a reviews on the new modem and I found this review posted.. I find it very interesting because it describes a issue where his sb8200 was having dropped internet and his neighbors where not and he mentions this is sensitive to t3 t4 timeouts and xfinity modems seems to handle network issues better ... interesting. Below a snip from that review on Amazon. The thing is that on the box its says xfinity compatible with the logo and all so xfinity must have approved this modem for their network I would think.
"My issues arose with my Xfinity service and resets, slow speeds (300Mbps Max down), etc. Xfinity sent out a tech and that did nothing. So another rech came and found a ton of ingress coming from 4 lines on my tap. He trapped them off and I was up and running with Gigabit speeds again. Then the resets started, at night almost every 10 minutes! It was only happening between 10pm and 7am average, EVERY NIGHT! I had more techs out, supervisors and more supervisors! After a month (and many hours of my time and speaking up) the issue was resolved as it was a bad line amplifier which was causing noise and caring my upstream to spike into the high 50s, which triggers resets on the modem and t3/t4 errors. Now my neighbors were having issues on certain channels and slow internet but their modems WERE NOT RESETTING! And we knew my modem wasn't bad as it was fine for over 12 hours a day with no errors at all in the log until night began to fall everyday. And In fact my neighbors never lost internet, EVER but my internet was almost useless at night time. So the Arris SB8200 is extremely sensitive to t3/t4 errors and the threshold for errors and resets is much higher for the Xfinity owned gateways and modems. Also Arris had out out a firmware update previously about severe sensitivity to t3/t4 errors and I had the latest version but I was still having issues so they still need to work on this. If you are experiencing issues with your Arris modem navigate to http://192.168.100.1 and you'll be able to see basic signal information, modem error logs, modem and firmware info. You can use this information and post it in the support forums to get help and diagnose any problems."
New modem is installed SB8200. I did a quick speed test and I am getting 950 mbps down and 40 mbps up. I brought up the Cable Modem status page and I wanted to know if anyone could help me with this but the last channel has millions of corrected and goes up a million every second. Is that normal for that channel? Also I have access to a spectrum analyser with this modem ... not that I know really what to look for but hey what the heck right? Modem has just been switched out.. info below:
Yes. That is the DOCSIS 3.1 / OFDM downstream channel for the delivery of the gigabit speed tier. There is a known issue with some makes and models of modem's signal measuring mechanisms where they improperly report the stats of that channel. It's also the nature of the beast with that channel having such a wide bandwidth spectrum.
Also keep in mind that those are corrected bit errors, not *uncorrected*.
Me thinks, firmware.
Yes and the firmware has to go from the manufacturer and then get approved by xfinity and then on to the modem. If the modem gets a firmware update from Comcast does that cause it to reboot or does it just sit in the modem until the next time the modem is rebooted.
In regards to the outage issue ... things so far are all good. The modem logs show one more set of "dynamic range window violation" and such that happened this morning but my outage detector did not detect any issues at that time so thats good and no t3 timeouts which seem to cause the real problems. The corrected/uncorrected are all good and whats kinda funny is the channel that has the bug with corrected showing millions has now settled on 80 and just sits there. If it was doing all those calculations you think it would have settled on 42 (I crack myself up sometimes)
If the modem gets a firmware update from Comcast does that cause it to reboot or does it just sit in the modem until the next time the modem is rebooted.
The CMTS /system re-boots the modem remotely.
Nothing new in the logs, a couple more uncorrectables, and no outages detected. It looks like the issue is resolved. It is frustrating that I don't know for sure in the end what the problem was, it certainly looks like two bad mb8600s, but what are the chances. It could also be that something was done on the line or maybe the mb8600 is sensitive to noise on the line.
Thanks EG for the helpful posts
Quite welcome ! Hope that things hold up for you ! Now closing this thread. Please post a new thread if the problem returns.