This is very practical and RFC3489 (http://www.ietf.org/rfc/rfc3489.txt http://www.ietf.org/rfc/rfc3489.txt) has a definition for this - "Port Restricted Cone N

This is very practical and RFC3489 (http://www.ietf.org/rfc/rfc3489.txt http://www.ietf.org/rfc/rfc3489.txt) has a definition for this - "Port Restricted Cone NAT". For the reference to some of the port restricted NATs, take a look at http://tools.ietf.org/html/draft-jennings-behave-test-results-01 http://tools.ietf.org/html/draft-jennings-behave-test-result... As for cultural expectation, yes, the port-restricted cone NATs are a pain.;-)