Aren't Microsoft already "standardizing" this with their Universal Plug and
Play (UPnP) architecture?
That's just midcom, which the IETF is standardizing. We
started before they did but Microsoft got there first and
worst (there's even midcom language in their documents). So
that's something that was started in the IETF and
expropriated. Note that it still handles incoming
connections pretty badly.
The UPNP "Internet Gateway Device" working group and the MIDCOM WG effort
started at about the same time, but the UPNP specification was published about
2 years ago, while MIDCOM is not quite finished yet. Looks like an interesting
case study for the "problem statement" working group...
I don't quite get the point on the handling of incoming connections --
basically, the UPNP/IGD specification has functions for reserving port
mappings, that allow a host behind a NAT to listen on an external port number.
The host can definitely receive incoming connections.
The UPNP/IGD approach has limitations: it is designed for a "home network"
rather than an enterprise network, and it will not work if there are two
"stacked NAT". However, it does solve a large fraction of the problem.
By the way, while Microsoft certainly contributed to the fundation of the UPNP
Forum, the UPNP/IGD is not exactly a Microsoft specification.
-- Christian Huitema