iTunes Sharing across VPN


Anyone know if it is possible to share your iTunes libray across a vpn connnection? I setup a vpn client between my ibook and my home firewal (Netscreen 5GT) and would like to be able to see the itunes library on my home PC. The sharing works fine when I am on the local network with my PC but not across the VPN so I am wondering how itunes sharing broadcasts and what would I need to do to share the library across a vpn that is not blocking any traffic.