[EarlKing]

Addressing each other by surname is something that occurs principally in the context of sports, but outside of that you'd just address someone by given name. That was the case as regards children addressing each other or teachers addressing students. Students addressing teachers, of course, would address them by Mr/Mrs/Ms. <surname>. There are some oddball cases where teachers insist their students address them by given name, though.

Also, you made me feel old.

[dmoy]

It is also used when there's name collision

If there's five people named John in the same class in school or the same team at work, it is not uncommon for all John to go by last name.

[EarlKing]

In my circle usually people would either go by their middle name or they'd very quickly earn themselves a nickname... although now that I think about it we did use lastnames for some guys. Whatever works, really. Nobody was a stickler about how they were addressed.

[lukas099]

The surname thing was extremely common even outside of sports at my high school.