Indeed, the protocol parser and the SCHC rules need to know about the UDP
TLVs if one wants to compress them.
But the same is true of all the other fields. I don't think this one
warrants a special notice.
What I insist on is that, if an implementation does not know of the UDP
TLVs, it will not reconstruct an erroneous UDP Length, even for a packet
that contains these TLVs, assuming that the protocol parser checks the UDP
and IPv6 lengths for consistency.
I think this last statement (“protocol parser checks the UDPand IPv6 lengths for consistency”) is the important point that needs to be explicitly mention in the document!
That way of phrasing it is dangerous - it implies that when the values differ there is some sort of error.
It would be more in line with current TSV efforts to standardize UDP options to say “UDP length can be compressed when it *can* be computed from the IP length” and that “it MUST NOT be compressed as computable otherwise”.
Joe |
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