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Slow Internet Speeds capped at around 33 Mbps

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Slow Internet Speeds capped at around 33 Mbps

The past couple days I've suddenly been capped at a maximum speed of around 33 Mbps.  I have the following plan: Performance Internet – Speeds up to 100 Mbps.  Before this I would actually reach speeds above 100 Mbps - more like 120 Mbps.  Now speeds reach a max 33 Mbps and sometimes drop to 5 Mbps which completely prevents me from working at home now.  


I've already called into xfinity tech support about the issue and they have tested and rebooted my modem remotely several times with not issues found.  I have also power cycled it and factory resetted it numerous times on my own.  The physical cable line is fine.  Nothing changed there and TV is working great.


Similar Issue:

I did read a previous post (link below) and I think I may have the exact same issue as everything described is the same.  Their problem apparently was a corrupt bootfile.  @EG and @ComcastJoeTru helped on this issue before.


My modem specs are as follows;

Netgear CM1100

Hardware Version 2.02
Firmware Version 6.01.07


Modem Connection Screen


Modem Event Logs


I'm hoping someone can take a look at the logs and see if the boot file being corrupted is in fact the probable solution.




Re: Slow Internet Speeds capped at around 33 Mbps

This may not be the root cause of the problem but it should be addressed nevertheless.


The upstream power is on the high side and it may be intermittently fluctuating even higher to out of spec levels. That can cause random disconnects, spontaneous 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.

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