<div dir="ltr"><br><br><div class="gmail_quote">2011/7/3 Arie Skliarouk <span dir="ltr"><<a href="mailto:skliarie@gmail.com">skliarie@gmail.com</a>></span><br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">
Hi,<br><br>The company I work at uses openvpn extensively. We settled on UDP-based protocol as it is more effective than TCP based.<br><br>Inter-Israeli VPN connection works perfectly all of the time, whereas international VPN has erratic behavior on at least one ISP. I suspect the ISP (XFone 018) dropping UDP packets occasionally during peak hours for following reasons:<br>
<ul><li>ICMP ping to the internet-facing IP number of the VPN router works properly all of the time</li><li>over-VPN ping to some server has about 50% packet loss during peak hour (tested at 23:00)</li><li>on different ISP at the same time there was no packet loss<br>
</li><li>over-VPN ping on the same ISP worked perfectly in the morning hours</li></ul>Have anyone else noticed the same behavior?<br>What is legal status of such network traffic policing?<br><br clear="all"></blockquote>
<div><br></div><div>There is a nice work about this by Udi Wienberg from TAU - <a href="http://www.eng.tau.ac.il/~udiw/papers/neutrality_miniconf.pdf">http://www.eng.tau.ac.il/~udiw/papers/neutrality_miniconf.pdf</a></div>
<div><br></div><div>In the presentation he gave, he showed several examples of traffic shaping, and the counter measures that ISPs take in order to prevent the clients from proving their traffic is shaped. One notorious measure is resetting TCP connections (so, if your provider is indeed shaping your traffic, it may be that even if you switch from UDP to TCP, you will still have a problem).</div>
<div><br></div><div>His work is about detecting such traffic shaping. I also found a site which helps you test for traffic shaping: <a href="http://broadband.mpi-sws.org/transparency/bttest.php">http://broadband.mpi-sws.org/transparency/bttest.php</a></div>
<div><br></div><div><br></div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex;">--<br><font color="#888888">Arie<br>
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<br></blockquote></div><br><br clear="all"><br>-- <br>Orna Agmon Ben-Yehuda.<br><a href="http://ladypine.org">http://ladypine.org</a><br>
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