On Nov 5, 2012, at 15:28, "Cao,Zhen (cz)" <[email protected]> wrote:
> On Mon, Nov 5, 2012 at 2:11 PM, Carsten Bormann <[email protected]> wrote: >> On Nov 5, 2012, at 13:56, "Cao Zhen (cz)" <[email protected]> wrote: >> >>> Hi Carsten, >>> >>> The problem you describe is cool. But in Lwig guidance document, I >>> remember there is a guidance saying we should avoid fragmentation if >>> we can. >> >> Yes, but how do you do that if you don't know the fragment size? >> Right now, you can only guess, and you'll likely try to guess >> conservatively, missing out on the opportunity to reasonably fill the >> packets. > > Only 6lowpan adaption is here in IETF, the MTU is 127 bytes, isn't it? That is the physical layer MTU. The specific combination of MAC layer overheads, adaptation layer overheads, and header compression gains can turn the actual initial fragment size number into anything roughly between 70 and 160 bytes. Note that this is more than a factor of two. Grüße, Carsten _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
