time-gai-connect.py

   A very short python program that measures TCP connection establishment
   times to a given hostname, using addresses returned by getaddrinfo().
   Arguments are a hostname, and optionally a port number, otherwise port
   80 is assumed.

   I wrote this program to help me measure real connection establishment
   times to dual stack (IPv4 and IPv6) destinations, to see how this
   affects address selection algorithms in operating systems and
   applications. Some modern algorithms (eg. Happy Eyeballs, Apple network
   stats based connection preferences) take these connection times into
   account when choosing destination addresses.

   Usage:

    time-gai-connect.py hostname
    time-gai-connect.py hostname portnumber


An example run (from a machine on the upenn campus) with the main
IETF webserver, www.ietf.org:

     $ time-gai-connect.py www.ietf.org
     2001:1890:123a::1:1e                     90.98601 ms
     12.22.58.30                              76.32303 ms


   Shumon Huque
   E-mail: shuque -at- upenn.edu
   Web: http://www.huque.com/~shuque/
   University of Pennsylvania.

   Copyright (c) 2011-2012 Shumon Huque. All rights reserved. This program 
   is free software; you can redistribute it and/or modify it under the same
   terms as Python itself.