It's great that we have fallbacks to ensure that tubes pretty much always successfully connect. But some applications may want to know whether or not the connection is likely to be high-latency and low-bandwidth.

This came up in discussion at the MeeGo Conference with a KDE games hacker I've woefully forgotten the name of (sorry). Some games—multiplayer Sudoku, for example—don't really care about latency or bandwidth, but for other games it's not really worth playing if a fast connection can't be established. So we could provide a way for the channel request to include { Fast: True } so that the request fails if a fast tube can't be opened, or something.

Of course applications can do their own connection quality monitoring, but it would be useful to have a really crude measure that clients can use supplied by the CM.