What is this

I have seen them labeled on the box as canister repeater. Don't know if that a regional term.

Looks like a "Potential Chili Pot" to me...except some fool probably put holes in the bottom!

My guess is the round can contains a repeater for high-speed, long-distance links (high for copper lines, not fiber). The main clue is the T3 in its designation.
https://en.wikipedia.org/wiki/T-carrier

Thanks guys

I call most utility objects above ground a "riser" and in this example "telephone riser"

Those are Apparatus Cases. They hold T1 or 56k repeater cards, but more than likely T1 repeaters. T3 (DS3's) aren't delivered on copper cables because they would require LOTS of these.

http://www.charlesindustries.com/main/te_cases.html

What everyone else said...."Repeaters".....

Communication's Box. These days communications includes telephone, internet and even cable, since you can order what gets delivered to your house, far beyond just broadcast.

Per One-Call, orange is communications.

Paul in PA