There's always something new and progressive in the free and open source software universe. Here's a roundup of some recent worthy happenings in the fun worlds of iptables and VoIP: getting SIP through iptables NAT firewalls, adding new modules to iptables with Patch-O-Matic, monitoring iptables in real-time, and a look at the excellent AstLinux, "the professional's PBX".
http://www.enterprisenetworkingplanet.com/netos/article.php/3638441