Random internet disconnects

The downstream power is on the low / weak side and it may be intermittently fluctuating even lower to out-of-spec levels. It's way out of spec on the OFDM channel (33) as is the SNR. 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 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 from Home Depot, Target, Wal-Mart, 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, abrasions, 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 !

Hello @user_5fb81w, thank you for taking the time to reach out on social media.  I understand your concern with the connection, and I'd like the opportunity to check into that for you.

To access your account, will you please send us a direct message with your full name and complete service address to “Xfinity Support”. To do so, click on the chat icon located at the top right of this forums page.

Here's the detailed steps to direct message us:

• Click "Sign In" if necessary
• Click the "Direct Message” icon (upper right corner of this page)
• Click the "New message" (pencil and paper) icon
• Type "Xfinity Support" in the to line and select "Xfinity Support" from the drop-down list
• Type your message in the text area near the bottom of the window
• Press Enter to send your message

I read that there is firmware with Comcast on this MB8600/8611 model. Some users experience the same but problem goes away once downgrade to lower speed from giga-speed plan.

It appears that this modem model is NOT listed as compatible devices any more from "Full list of Compatible Devices" published by Comcast on 11/23/2023 for "Xfinity 10G" network.

My question is that any Comcast tech support team member from this forum could help to confirm whether this model still will be considered as compatible & support provided for 1Gbps and/or sub-1-Gbps internet plan users or not?

not everyone needs "10G" and for sure they are still many Comcast customer depends on this model for internet connection of sub-giga-speed.