HTTP Measurements

Connection establishment is expensive. It uses both unneccessary resources (on both client and server side) and it costs time. During the day I experience _large_ round-trip-times to remote sites (up to 1000 msec, now (evening) I have min/avg/max = 341/604/848 to www.ncsa.uiuc.edu )

All the handshaking involved in setting up the connection is responsible for most of the loading time of any page with lots of small icons.

I made a measurement how long it takes for me to fetch the GNN home page. I traced the packet-flow using tcpdump.

I have made three postscript plots displaying

Please get the files and notice that there are a lot of pauses where nothing is transferred.

For a better performace it is vitally important to reuse http-connection.


Otmar Lendl (lendl@cosy.sbg.ac.at)
Last update: Wed Feb 16 18:18:46 MET 1994