filtering tcp/udp ports

[giulio]

Hello i need to migrate traffic from servers to internet, from firewall to webgateway. I have different type of traffic, http/https, tcp high ports, udp ports. For example, for traffic on port 22, i enable the port 22 in listening; and then how can i filter source, destination and port ? Simply creating a whitelist with also port as criteria to be filtered ? Is possible to provide an example ? (this should be valid for any kind of tcp port) And, udp port is in some way proxable ? For example, dns traffic or ntp traffic can be accepted and forwarded to the remote site ? Thanks Giuliano Buraschi