The problem: logging in to a remote system with a cryptographic
solution such as lsh or ssh takes time, due to the computationally
expensive key exchanges that occur when the connection is
established. It is common to trigger a lot of remote logins while
using remote CVS, which makes it painfully slow compared to having the
repository locally.
The solution: reuse the secure tunnel once it has been
established. fsh is a drop-in rsh-compatible replacement for ssh that
automatically resuses ssh tunnels.
WWW: http://www.lysator.liu.se/fsh/