Client

apt-get install rsync
rsync -e ssh -p **** -av SOURCE_DIR SSH_USER@SSH_HOST:REMOTE_DIR

In the example above, rsync will use ssh on port 8023

rsync -av --progress --inplace --rsh='ssh -p8023' somefile user@host:somedir/

Server

apt-get install rsync
cp /usr/share/doc/rsync/sample-rsyncd.conf /etc/rsyncd.conf

configure it

http://www.fredshack.com/docs/rsync.html