Guys Apologies for cross posting Over the last couple of months Jan and I have been committing a lot of H.460 NAT support into H323plus and GnuGk . H.460.18/.19, Multiplexing, Traversal Zones and H.460.23/.24/.24A/.24B and just recently H.460.17. I have written with Jan's assistance an ordinary person guide to NAT, the types of NAT and the logic behind H.323 NAT Traversal solutions. It briefly explains exactly what all these standards mean and how they fit together to provide a complete NAT Traversal solution. h323_nat_fw_solution.pdf <http://hive.packetizer.com/users/h323forum/specifications/h323_nat_fw_solut ion.pdf> Simon