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Providers differ across countries.<br>
<br>
European competition laws are interpreted quite differently in
different countries. AFAIK, Deutsche Telekom and France Telecom are
monopolies. ISPs there therefore use the same infrastructure. BT is
not. Here there are differences between ISPs.<br>
<br>
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<a href="http://www.samknows.com/broadband/exchange/MRPOY">http://www.samknows.com/broadband/exchange/MRPOY</a><br>
<br>
Shows service availability in the area where I am, immediately to
the south of the Manchester conurbation. <br>
<br>
Recommendations are also affected by service cost. In this country,
BT increases its prices once or even twice a year by just below the
ten per cent threshold where the regulator takes an interest. Sky
and TalkTalk then follow. Individuals then have to make decisions
based not just on shaping policy, the type of CPE supplied, and TV
channels specific to the provider, but on cost.<br>
<br>
Negotiation on cost involves a yearly conversation with the
provider, and cashback offers available elsewhere. Recommendations
are therefore problematic.<br>
<br>
<br>
<br>
<div class="moz-cite-prefix">On 29/12/13 08:54, Dave Taht wrote:<br>
</div>
<blockquote
cite="mid:CAA93jw4FWXopWycqgOBfMtf80W9QFh1jejyhdgmOFxO-N=xXxA@mail.gmail.com"
type="cite">
<pre wrap="">I would like it if we had a couple per-provider recomendations and
relevant discussion.
On Sat, Dec 28, 2013 at 11:36 PM, Sebastian Moeller <a class="moz-txt-link-rfc2396E" href="mailto:moeller0@gmx.de"><moeller0@gmx.de></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">Rich Brown <a class="moz-txt-link-rfc2396E" href="mailto:richb.hanover@gmail.com"><richb.hanover@gmail.com></a> wrote:
</pre>
<blockquote type="cite">
<pre wrap="">QUESTION #2: How does CeroWrt use info gleaned from the link layer
adaptation?
</pre>
</blockquote>
<pre wrap="">
The link layer adaptations work in correcting the kernels estimate of a packets behavior on the wire. In the tc_stab case the kernel calculates the effective size of the packet on the wire, that is it pretends the packet is larger than it really is, so for a given bandwidth it estimates the correct time it takes for that packet to be actually transmitted. In the htb_private case the kernel keeps the packet's size (more or less) intact but adjusts its estimate of the packets transmit rate. Both methods boil down to the same idea, make sure the packet scheduler will only send packet N+1 after packet N has just cleared the wire.
</pre>
<blockquote type="cite">
<pre wrap="">
Specifically, the link layer adaptation all seem to be designed to
compute the actual time it takes to transmit a packet, accounting for
Ethernet & PPPoE header bytes, other overhead, and ATM 48-in-53
framing.
</pre>
</blockquote>
<pre wrap="">
And the annoying size dependent padding of the last ATM cell.
</pre>
<blockquote type="cite">
<pre wrap="">
How does CeroWrt use this time calculation? Does it simply make sure
that the target time doesn’t get too low for a particular flow’s queue?
</pre>
</blockquote>
<pre wrap="">
Thanks to the link layer adjustments (lla) cero now estimates the correct time each packet takes and will not send any faster than the shaped rate allows. If no lla is performed cero would overestimate the link capacity, send more than expected and potentially fill the modems bloated buffers. Traditionally people tried to reduce their shaped rate by >10% to at least account for the 48 in 53 framing, but failed miserably for small packets since overhead and padding can more than double the wire size of a packet. Note that ACQ packets typically are small as are voice over IP packets.
I hope this helps
Sebastian
</pre>
<blockquote type="cite">
<pre wrap="">(I could imagine that a short packet over ATM would take 2x the (naive)
expected/calculated time for a packet of that length, and that flow
would be penalized. Is there more to it?)
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</pre>
</blockquote>
<pre wrap="">
Hi Rich
--
Sent from my Android phone with K-9 Mail. Please excuse my brevity.
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</pre>
</blockquote>
<pre wrap="">
</pre>
</blockquote>
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