Apart from bugfixes (like a tunable parameter to get rid of UDP buildup in system buffer due to sample rate skew) there has been some intersting discussion on tunnelling through NAT. I just noticed that speak-freely@ doesn't have a web archive. I'll be happy to forward relevant posts to anyone interested (privately, or dump them to cpunx-news to you can read them up from web archives). On Mon, 27 Jan 2003, Steve Schear wrote:

I'd love to use SpeakFreely but one of its quirks is that it uses two different ports to initiate and respond to connections and communicate. Like many others I uses a firewall appliance. And like many firewall users we find features lacking for configuring our firewalls so that incoming traffic on one port can be associated with outgoing traffic from another. About two years ago I thought a programmer I knew was going to fix this, but it never happened. Hint: who ever takes up improving SpeakFreely, please add this to the change list.