Allowing Skype using Layer 7 rules
By default, Skype uses undefinable Ports and IP addresses to make and receive calls. Where this doesn't work, it falls back to HTTPS URLs containing an IP address. Allowing Skype via either of these methods can also allow certain types of VPN and Anonymous proxy.
Given the Smoothwall already has Layer 7 signatures for Skype, it would be a great benefit to be able to leverage these for allowing traffic, rather than solely for blocking traffic. This way, Skype could be allowed, whilst maintaining strong Firewall and Web Filtering policies.