[e2e] Congestion control as a hot topic in IETF

Thu Mar 7 15:22:21 PST 2013

hunh?

a wire is just a channel no different from free space
except for interference and possibly slower than speed of light RF
propagation, and, depending on technology, lower interference and
lower path loss

the channel is irrelevant to this discusson, except that a wireless
channel may be shared so you can see contention for the receive
antennae (some people talk about contention for the media too, but
that's a figment of the technology of choice for MAC)...

so i have no idea where you think packets are stored except in
senders' and receivers' NICs' buffers....

you need to haev a REALLY long haul link to get a lot of packets
in transit (propagation) - these are unusual cases (satellites)

basically (comms #101) - you have the 
packet serialisation time (s=clock speed*packet length)
and you have the packet propagation time (p=link geodistance / c)

so the case of packets in transit is plural, is when p/s  > 1
which is not too many cases...

anyhow that's not what congestion or contention are about

In missive <51390F43.9090700 at web.de>, Detlef Bosau typed:

 >>Am 07.03.2013 23:02, schrieb Jon Crowcroft:
 >>>
 >>> What has the wireless link got to do with it? The same is true of a 
 >>> wire. The contention is for shared media, or shared buffer.

 >>Hm. Does a wired link always keep only one packet or less? ;-)

 >>This is the difference here: The capacity.

not really.

 >>
 >>-- 
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 >>Detlef Bosau
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 >>    <div class="moz-cite-prefix">Am 07.03.2013 23:02, schrieb Jon
 >>      Crowcroft:<br>
 >>    </div>
 >>    <blockquote
 >>cite="mid:CAEeTejKADW=djTrj=H3hGEfYo62B2R3KvHgCM_m3W9JeaPSGhw at mail.gmail.com"
 >>      type="cite">
 >>      <meta http-equiv="Context-Type" content="text/html;
 >>        charset=ISO-8859-1">
 >>      <p>What has the wireless link got to do with it? The same is true
 >>        of a wire. The contention is for shared media, or shared buffer.</p>
 >>    </blockquote>
 >>    <br>
 >>    Hm. Does a wired link always keep only one packet or less? <span
 >>      class="moz-smiley-s3"><span> ;-) </span></span><br>
 >>    <br>
 >>    This is the difference here: The capacity.<br>
 >>    <pre class="moz-signature" cols="72">-- 
 >>------------------------------------------------------------------
 >>Detlef Bosau
 >>Galileistra&szlig;e 30   
 >>70565 Stuttgart                            Tel.:   +49 711 5208031
 >>                                           mobile: +49 172 6819937
 >>                                           skype:     detlef.bosau
 >>                                           ICQ:          566129673
 >><a class="moz-txt-link-abbreviated" href="mailto:detlef.bosau at web.de">detlef.bosau at web.de</a>                     <a class="moz-txt-link-freetext" href="http://www.detlef-bosau.de">http://www.detlef-bosau.de</a>
 >>
 >></pre>
 >>  </body>
 >></html>
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 >>--------------070804030003020405080909--

 cheers

   jon