Training Livestream - Understanding Replication in UE4 - March 21 - Live from Epic HQ

Question: How can you host multiple games at the same time on shooter game? I am thinking about it as a single dedicated server per map. So when I have two different levels loaded at the same time I am a little confused. Since it is using online subsystem=null are these separate levels just sessions? If so how many of these sessions can shooter game run at the same time?