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On 03/07/11 08:28, Arie Skliarouk wrote:
<blockquote
cite="mid:CAM_hoo=XHhP0aC+CUQUqjeLjBDmAzX9LmnU5rOFvQTQSEpiqMQ@mail.gmail.com"
type="cite">Hi,<br>
<br>
On Sun, Jul 3, 2011 at 08:02, shimi <span dir="ltr"><<a
moz-do-not-send="true" href="mailto:linux-il@shimi.net">linux-il@shimi.net</a>></span>
wrote:<br>
<blockquote style="margin: 0pt 0pt 0pt 0.8ex; border-left: 1px
solid rgb(204, 204, 204); padding-left: 1ex;"
class="gmail_quote">If you want, prior to calling them, to
combat them with their own weapon, thankfully there's a UDP
protocol that probably no ISP would want to degrade; Try
switching to port 53 :-)<br>
</blockquote>
<br>
I think that would not work as I observe frequent name server
errors at exactly same periods (I am using Google's free DNS
servers 8.8.8.8 and 8.8.4.4). Hmm, need to switch to the local DNS
servers...<br>
</blockquote>
If that's the case, then your implied accusation, that they are
treating traffic differently based on protocol, might actually be
false. Have you tried big ping packets (size > 100)? You can send
them using "ping -s 256".<br>
<br>
If that's the case, then it's "business as usual", and TCP packets
probably have the exact same problems.<br>
<br>
As for why communication over the VPN seems slower - it might be
that you have not lowered the MTU of connections going over the VPN
link. If that's the case, packets get fragmented, and a single TCP
packet turn into two UDP packets. If that happens, the chances of a
drop are doubled, which means that the chances of a retransmission
are doubled too. Try to make sure that the MTU of the TUN interface
is lower than the MTU of the actual interface where packets are
really sent (ppp0?), and that there is a firewall rule to squash the
MSS to the MTU.<br>
<br>
Shachar<br>
<pre class="moz-signature" cols="72">--
Shachar Shemesh
Lingnu Open Source Consulting Ltd.
<a class="moz-txt-link-freetext" href="http://www.lingnu.com">http://www.lingnu.com</a>
</pre>
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