concurrency and Server::TCP

[vidals]

I have an app that I wrote which is sensitive to being overwhelmed by
POE's multitasking. I couldn't figure out a way to "slow" it down and
run serially, so I set Concurrency = 1 like so:

POE::Component::Server::TCP->new(
   Address              => ListenAddr,
   Port                 => ListenPort,
   #Alias               => 'name',
   Concurrency          => 1, # 1 means run sequentially; default -1?
(infinite)
   ClientInput          => \&process_input,

If I run it with Concurrency 1, then I see that ClientInput only
accepts input chronologically - one at a time. Where does POE store
the queued requests of ClientInput? There seems to be an implied
buffer somewhere?

--Gil Vidals