On Apr 2, 2014, at 11:14 AM, Joe Abley <jab...@hopcount.ca> wrote: > Hi all, > > It's common wisdom that a datagram that needs to be fragmented between > endpoints (because it is bigger than the path MTU) will demonstrate less > reliable delivery and reassembly than a datagram that doesn't need to be > fragmented, because math, firewall, other, take your pick. > > Is anybody aware of any wide-scale studies that examine the probability of > fragmentation of datagrams of different sizes? > > For example, I could reasonable expect an IPv4 packet of 576 bytes not to be > fragmented very often (to choose a size not at random). The probability of a > 10,000 octet IPv4 packet getting fragmented seems likely to be 100%, if we're > talking about arbitrary paths across the Internet. > > What does the curve look like between 576 bytes and 10,000 bytes? > > I might expect exciting curve action around 1500 bytes (because ethernet), > 1492 (PPPoE), 1480 (GRE), etc. But I'm interested in actual data. > > Anybody have any pointers? IPv4 and IPv6 are both interesting.
Seems a good thing for RIPE Atlas probes to measure. But they are probably not generally connected to representative networks (read: poor networks). -d
