Iljitsch, >But the part that really bothers me is that there will ALWAYS be >fragmentation even when the source host would have been perfectly >capable of reducing its packet size.
Turning back to this, the current SEAL draft is silent on behavior in the face of persistent fragmentation. From "Fragmentation Considered Harmful", the pain point is gross fragmentation in the presence of congestion, since the loss of a single fragment will result in the whole packet being retransmitted causing yet further congestion. Approaches to handling this include 1) drop large packets, and tell sources to start sending smaller ones, 2) treat the loss of fragments as a congestion indication, 3) some combination of the two. 1) will always result in loss, and can saddle sources with a too-small packet size indefinitely (or for 10min's at least). Plus, there may be sources that cannot reduce their packet sizes below a certain threshold, in particular 1280 bytes for IPv6. 2) seems like a more tenable approach, but the best answer may lie somewhere in-between, i.e., approach 3). The next SEAL draft version will discuss this. Fred [EMAIL PROTECTED] > >Iljitsch >_______________________________________________ >Int-area mailing list >[email protected] >http://www.ietf.org/mailman/listinfo/int-area > _______________________________________________ Int-area mailing list [email protected] https://www.ietf.org/mailman/listinfo/int-area
