On May 12, 2019, at 15:54, Barry Leiba via Datatracker <[email protected]> wrote: > > Why is DTL the length *minus 1*? Doesn’t that invite mistakes? Is there a > reason not to make it the length, and to say that 0 is not a valid value?
Fundamentally, a small integer encoded into a bitfield is best encoded as a value starting from 0, instead of creating holes at the bottom *and* the top. Also, in this case, the 4-bit value encoding DTL can be between 0 and 15, so the length in bits could be 0 to 60, which is not enough for 64 bits. So adding one sounds fine, even if you believe holes are good. But then, I don’t understand why both DT and OTD are said to be “8..64” bits — that needs 15 possible values, not 16; OTL has only 3 bits (which cannot express 15 possible values, which are probably not needed anyway), and the example for OTL has a DT of 4 bits. Grüße, Carsten _______________________________________________ 6lo mailing list [email protected] https://www.ietf.org/mailman/listinfo/6lo
