Good afternoon and welcome to the Rogers Community Forums @Joelien
Intermittent speeds issues are quite disruptive ! My understanding of the T3 timeout errors, is that it's a normal functionality of the modem communicating with the CMTS, even though it's logged as a critical error. Usually, the modem documents it when it doesn't receive response to 16 ranging requests. Generally you can ignore them, unless they are happening quite frequently. Are you currently experiencing any interruptions with your service?
This may not be the modem specifically.
(though it could be say the signal is dropping to your whole unit and the modem is dropping).
That its in a condo, my guess may be something else.
That at specific times, when there is heavy usage from other people in the condo, that you may be running into multiple users the same wireless channels and getting interference.
There is no fix for that. As I understand there is a piece of equipment in your unit that transforms signal from fiber-optical wire to coaxial and this equipment is what causes problems. Try calling rogers maybe they will help.
A) get a tech out again and test all the equipment at the spot where it splits where it comes into the building.
B) If its a wireless issue, you need to narrow down whats in use most heavily in your range.
You can use a software like
(It will find all the local wireless. If you select all of them, it will pop up a window, which you can then go over to the 2.4 and 5ghz tabs. It will show you what channels each of them are on as well as the strength.)
You will want to log into the rogers router, and go into the wifi settings. You'll want to then change it to a channel which is not overlaped or at least the less overlapped from others in the area.