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Center for Applied Internet Data Analysis
Analysis of Fragmented Packet Traffic

About Packet Fragmentation...

Packet fragmentation occurs when a packet too large for the subsequent link reaches a network interface and is broken up into a series of fragments the size of the MTU of the ensuing link. Packet fragmentation has a negative impact on network performance for several reasons. First, a router has to perform the fragmentation - an expensive operation. Second, all the routers in the path between the router performing the fragmentation and the destination have to carry additional packets with the requisite additional headers.


Glossary

chart showing packet fragmentation
Packet:
A discrete unit consisting of data that needs to be transported across a network and information necessary to direct that data to its destination.
Payload:
The data that needs to be transported across a network.
IP header:
Information prepended to the payload that allows the payload to reach its destination, including the source and destination and a checksum for error detection.
MTU:
Maximum Transmission Unit -- the largest size of packet that can be transported across a given link.
Path MTU:
The smallest MTU of all the links in a path.
Fragment:
When a fragment is larger then the next link, it is broken up into pieces called 'fragments' that are no larger than the MTU of the next link.
Fragment Series:
The set of fragments that composed a single original packet.

The following pages contain graphs and analysis of fragmented packet traffic on several links:


Analysis by Trace
UCSD-CERF
The Poster I presented at the SDSC Student Intern Poster Session. (contains data from several traces)
May 17-June2, 2000
Ames Internet Exchange
Coming Soon!
Analysis by Data Type
Fragments per Fragment Series
Sizes of Fragment Series
First Fragment Sizes
Last Fragment Sizes
Original Packet Transmission Time
  Last Modified: Tue Mar-24-2009 13:58:07 PDT
  Page URL: http://www.caida.org/research/traffic-analysis/fragments/index.xml