I knew that it should be possible use an outgoing ssh connection to login on a machine behind a firewall. But I never got it to work until now. While surfing through the developerworks pages at IBM.com I found an article with a short and clear explanation of how it works. Click the link if you like to know more;
http://www.ibm.com/developerworks/linux/library/l-10sysadtips/?S_TACT=105AGX03&S_CMP=ART#T5
