> joel jaeggli <mailto:joe...@bogus.com> > 6 June 2013 22:19 > On 6/6/13 4:09 PM, Fernando Gont wrote: >> On 06/06/2013 06:20 PM, Nalini Elkins wrote: >>> So, if we are talking about the MTU of the local egress interface, then >>> since, I believe, the minimum MTU size for IPv6 is 1,280, then all >>> devices should be prepared to examine up to 1,280 bytes to get the L4 >>> header? >> In theory, yes. In practice, it wouldn't make much sense, probably (most >> of the packet containing overhead?). > There's a question you can pose to an asic designer... What does it > cost at this point to extend the header processing from 53/64/128/256 > bytes. bearing in mind also that part of the reason that the space > already has increased is due to encapsulation, label-in-label q-in-q > so the ipv6 header is not the only thing competing for more room. >> Cheers, > May I suggest some other questions:
Does size matter? Or is the complexity of the ASIC implementation of a header chain parser more heavily influenced by the fact that the header chain is defined as a linked list of type-length-value items that can be built up in any number of valid combinations, and so has to be traversed and interpreted at every individual link? What if the most common individual TLV option tokens were standardized further? And the transmission order fixed? What if the most common individual extension headers were standardized further? And the transmission order fixed? Would this help make hardware parsing possible/economic? regards, RayH -------------------------------------------------------------------- IETF IPv6 working group mailing list ipv6@ietf.org Administrative Requests: https://www.ietf.org/mailman/listinfo/ipv6 --------------------------------------------------------------------
