I'm in the process of installing network and telecom wiring in my house. I'd like to install several conduits from the basement to attic. But my preferred path requires me to drill several holes in the top plate of the main floor center interior wall which I believe is load-bearing. It sits directly above the steel beam in the basement, and the second floor joists rest on it. I've attached a picture.

I would like to drill two or three 2 1/4" holes in the same stud cavity, through the sole plate and top plate. The wall studs and top plate (double) are 2x6.

I read IBC 602.6.1 which seems to allow up to 50% of the width of the top plate to be notched or cut away without the need for any metal straps. But I am very concerned about affecting the structural integrity of the wall and the house. Should I be? Or can I happily go ahead and start cutting?

Would adding a strap to one side of the top plate add any additional strength? I'd rather not open up the other side of the wall to strap the other side.

Thanks for any help you can provide!

I don't see any problem as long as the hole you drill is near the center of the top plate. The top plate isn't a beam, really...it just acts as a nailer and a horizontal tie. Round holes are much better than notches, and you're below 50% anyway.

What I see is TGI joists in the middle of the wall. You can drill in the center like you said if your running through them, But you cannot drill into the block on the top or the bottom of the joist. Doing so will ruin the joist.
Also why such a large hole? You would be better served drilling a few more smaller holes if need be. The less wood removed the better.

Drilling the top and bottom plate like Richard said however should pose no issues.

Why so many holes, and so large? Have you looked into wireless options, which are getting better and cheaper every day?