pbnc runs in userland and acts as a simple TCP
port forwarder. It has a single-threaded design
which uses select() instead of forking. It can
handle multiple targets with a theoretically
unlimited number of clients, and it supports
simple IP-based access control. Since pbnc works
on the network level, it does not care about the
application protocol. It can forward FTP (control
connection), SSH, HTTP, and all other protocols
that use TCP communication.
