Some further points...
On 6/1/2012 7:45 PM, Masataka Ohta wrote:
Joe Touch wrote:
Existing routers, which was relying on ID uniqueness of atomic
packets, are now broken when they fragment the atomic packets.
The recommendation in this doc - that such sources MUST rate-limit - is
to comply with the ID uniqueness requirements already in RFC791 that
this doc does not deprecate - e.g., its use to support fragmentation.
It means that the uniqueness requirements must be loosened.
This document does that for atomic datagrams. We discussed whether it
was realistic to change the requirements for non-atomic datagrams in
INTAREA, and decided it wasn't.
Another example is that, when route changes, routers
fragmenting atomic packets may change, which means rate
limiting does not guarantee ID uniqueness.
Rate limiting (of non-atomic datagrams) is at the source, which ensures
ID uniqueness regardless of where they are fragmented.
Routers already should not be fragmenting atomic datagrams, as has been
noted.
Joe