On Monday 10 November 2008 09:39:31 ext Christian Vogt, you wrote: > endpoint independent mapping and filtering enables address referrals > between application instances (which use the same port number). This > advantage is independent of the transport protocol and the connection > model. The exceptions you are listing are special cases for NAT'ing > in general, not only with regard to the usefulness of endpoint > independent mapping and filtering. I don't disagree... Lets say that endpoint independent mapping is one half of a solution. We need another half: either a "simultaneous hole punching" mechanism, (and/)or endpoint independent _filtering_. With neither of these, address referrals from endpoint independent mappings are essentially unusable. As we have painfully learned in MMUSIC, this is not completely obvious. It works rather well for UDP, but it is poorly supported for TCP in the real world. And then DCCP had to be explicitly extended, as it did not support it at all. If we assume that all IETF transports will support simultaneous hole punching, then yes, endpoint independent mapping. -- Rémi Denis-Courmont Maemo Software, Nokia Devices R&D _______________________________________________ Ietf@xxxxxxxx https://www.ietf.org/mailman/listinfo/ietf