real-world data about fragmentation

Wed Apr 2 19:30:11 UTC 2014

This isn't a direct answer to the question, but I find this paper pretty useful (even though it is dated now):

  Beyond Folklore: Observations on Fragmented Traffic
  by Colleen Shannon, David Moore, and k claffy
  IEEE/ACM Transactions on Networking, December 2002
  http://www.caida.org/publications/papers/2002/Frag/frag.pdf

(Bill, I'd be curious to see your AINTEC slides, too.)

-- Jen

On Apr 2, 2014, at 2:50 PM, bmanning at vacation.karoshi.com wrote:

> 
> I can send you a copy of an invited presentation at AINTEC from 2009.
> 
> /bill
> 
> 
> On Wed, Apr 02, 2014 at 02:14:22PM -0400, Joe Abley 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.
>> 
>> 
>> Joe
> 