Not completely sure what your getting at...
The amount of players that can be held on a server depends on the connection and the specifications of the server running it
Better connection + more RAM + better CPU = more players
It's hard to hold too many people without lagg
He is asking why doesn't DoD:s have 64 player servers, like say, CSS.
I honestly don't know, but It takes a massive box to run a server with 64 people on it. CSS has less explosions and whatnot than DoD:S so that could be a reason.
i think u need to play some css zombie
Why doesnt Dods have it. maps like donner and strand sucks cause its too big.