Hi, All, This is a 'general' question on LnS and UDP hole punching. Info about UDP hole punching can be found here: http://en.wikipedia.org/wiki/UDP_hole_punching General speaking, It allows an effective P2P connection for 2 clients both behind NAT. An example is Skype. So, to make it work, client A (behind Nat A) should connects to a port of Nat B (say, 50000) and vice verse for client B. The question is: the port on Nat B (50000) is actually a random number and by default LnS blocks all other UDP connections except the allowed ones. So, to let these kinds of cnnections (Skype, etc ) fully work, seems LnS has to allow ALL UDP connections. Any comments, corrections would be greatly appreciated.