Re: How to transport BFCP in the presence of NATs

[[e-mail]]

On Wednesday, July 28 2010, "Joerg Ott" wrote to "Jukka Manner, [e-mail]" saying:

> this should be the preferred approach rather than doing a special
> version of every application protocol to also run over UDP -- which
> would just be calling for trouble, IMHO.

Do you mean specifically GUT, or generally something that allows tunneling
of TCP over UDP?  Other options in that space would be some sort of
peer-to-peer Teredo, or draft-baset-tsvwg-tcp-over-udp.  Each of these makes
different choices about the tradeoff between generality and overhead, and
it's not clear to me which would be the best option for this functionality.

The concern for BFCP specifically is that these ideas are all currently, at
best, individual author drafts, which would need not only to be standardized
but also to have documents written defining their use in SDP <proto> fields
and ICE candidate addresses.

Given how long this discussion has been going on already, I don't think
anyone imagines this would be a quick process.  The community that uses BFCP
is running into problems with peer-to-peer TCP communication in their
currently deployed networks, and the feeling among much of this community is
that progressing draft-sandbakken-xcon-bfcp-udp would be a much more
expedious process than getting consensus on a generic TCP-over-UDP
mechanism.

That said, I agree that having a general mechanism would be greatly
preferable, and going forward we'd be much better off if we starting having
serious discussions of this mechanism rather than having to revisit this
problem for all the protocols that come along in the future.  (And if it
does manage to progress quickly, but BFCP-over-UDP bogs down or runs into
trouble, the question of how to transmit BFCP could be revisited.)

-- 
Jonathan Lennox
[e-mail] / [e-mail]