Re: Updated UDP tunneling specification: draft-fairhurst-6man-tsvwg-udptt-01

[Stig Venaas <stig at venaas.com>]

I think this is a good idea, just some minor comments.

The draft says that the checksum will usually be constant for a UDP
flow. This is nice. For some tunnels it can even be computed at
configuration time (when the end-points are determined). I guess
the main case where this isn't the case, is when some datagrams
are fragmented but not all).

Regarding middleboxes. It says:

   o  Middleboxes SHOULD NOT truncate IPv6 datagrams where the IP length
      exceeds the Length specified in the UDP Header.

I guess some middleboxes might currently also just discard them? Or
maybe discarding is a kind of truncation :) I also wonder whether it
would be better to say MUST? At least they cannot support UDPTT unless
it is a MUST. Or at least a MUST when the length is 8.

Stig