> First is, the change of MTU was not one of 576 to 1280. I think he was talking about changing the minMTU of Steve Deering's Simple IP from 576 first into the mistaken 1500 and then into 1280 in the process of turning it into IPv6. http://tools.ietf.org/html/draft-deering-sip-00 (BTW, is that process documented anywhere? RFC1710 doesn't seem to mention the MTU.)
> The other point is, I don't see how transparent adaptation layers are an > issue at all? I don't think anyone is saying that it's impossible to transmit > IPv6 over ATM cells? Or are they? The problem comes up where the transparency is a leaky abstraction (http://en.wikipedia.org/wiki/Leaky_abstraction). For ATM, the abstraction was not very leaky as the performance impact of sending an MTU-size packet was negligible (at least for the more recent cases of ATM). For the constrained networks Ran and I are interested in, the performance impact of adaptation layer fragmentation can be significant, and application layer protocols that get to choose their packet sizes can benefit quite a bit if they know this fragmentation is taking place and what packet sizes are the thresholds. Please read the short ALFI draft for more background. http://tools.ietf.org/html/draft-bormann-intarea-alfi-03 http://www.ietf.org/proceedings/85/slides/slides-85-intarea-1.pdf Grüße, Carsten -------------------------------------------------------------------- IETF IPv6 working group mailing list [email protected] Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
