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<channel>
<title>MavEtJu&#39;s Distorted View of the World</title>
<link>http://www.mavetju.org/weblog/</link>
<description>MavEtJu&#39;s Distorted View of the World</description>
<dc:language>en-us</dc:language>
<dc:creator>weblog@mavetju.org</dc:creator>
<dc:date>2012-04-22T11:22:05+10:00</dc:date>
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<item>
<title>iPhone dock bar</title>
<description><![CDATA[
<p>
The iPhone home screen has four icons stuck at the bottom of the
screen. For the last year I had there Safari, Mail, Phone and
Facebook.

</p><p>
Yesterday I swapped Facebook for Podcaster, which I have been using
more frequent in the last four months.

</p><p>
Facebook is for people who are bored.<br>
Podcasts are for people who want to learn!

</p>]]></description>
<guid isPermaLink = "false">00336@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00336.html</link>
<category>iPhone</category><category>Happiness</category>

<dc:date>2011-09-08T08:00:00+10:00</dc:date>
</item>
<item>
<title>Morrison Gedicht - Twee</title>
<description><![CDATA[<pre>
ik wou dat ik een oma had
die ik soms zomaar op mocht bellen
en die 's avonds bij m'n bedje zat
om mij een sprookje te vertellen

maar oma's hebben allemaal al iemand
voor wie ze oma kunnen zijn
ze zitten dan wel in tehuizen
maar elke zondag is het kamertje te klein

dan komen ze allemaal op visite
en vragen of ze een zwaantje vouwt
en als ze 's avonds moe gaat slapen
weet ze dat er iemand is die van haar houdt

hoe zou het dan toch komen
dat heel veel oma's eenzaam zijn
en van hun kleine kinderen dromen
die nu veel groter en verhinderd zijn

al die oma's die truien breien
waarvan niemand zegt: wat fijn!
die hoeven me dat truitje niet te geven
maar willen ze alstjeblieft mijn oma zijn?

Morrison
</pre>]]></description>
<guid isPermaLink = "false">00335@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00335.html</link>
<category>Happiness</category><category>Memories</category><category>Weeshuis van de Hits</category>

<dc:date>2011-08-04T16:00:01+10:00</dc:date>
</item>
<item>
<title>Morrison Gedicht - Een</title>
<description><![CDATA[<pre>het is al bijna avond
wat gaat zo'n dag toch gauw
ik klim zo in mijn bedje
en dan
denk ik weer aan jou

dan lig ik stil te luisteren
naar de geluiden om me heen
dan hoor ik
zoemen tikken fluisteren
want ik lig hier niet alleen!

soms vertel ik mijn avonturen
aan Tiberius
da's een bromvlieg
en die woont op het kozijn
dan snort ie heel tevreden
want als er iemand tegen 'm praat
dat vindt Tiberius hartstikke fijn

vandaag ook Ricky nog gesproken
die woont bij de kersenboom
het is een soort van rups
maar hij wil later vlinder worden
net als zijn vader en moeder
en zijn tante en z'n oom

zelf wil ik
als ik later groot word
proberen klein te blijven
omdat Tiberius en Ricky anders
bang voor me zijn

dan blijf ik ook dichter bij
de bloemen
en zal ik altijd
gelukkig zijn

Morrison
</pre>]]></description>
<guid isPermaLink = "false">00334@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00334.html</link>
<category>Happiness</category><category>Memories</category><category>Weeshuis van de Hits</category>

<dc:date>2011-08-04T16:00:00+10:00</dc:date>
</item>
<item>
<title>My mallet finger - Wednesday 15 June 2011</title>
<description><![CDATA[
<p>
Last week it was decided that my mallet finger had to be fixed via
an operation during which I will get two wires inserted into my
finger: One below the nail which will push the broken piece back
against the bone, and one through the upper bone and halfway the
middle bone so that bone doesn't move anymore.

</p><p>
Today was the big day. We had to be in the hospital at 08:30, which
is about half an hour before Dirkie and Hanorah go to school. So
they slept with their grandparents and were very excited about the
fact that they got breakfast in a plastic bag in the car on their
way to school. I wish everybody was so easily pleaseble.

</p><p>
When you made the appointment to go to the hospital, you know from
the moment you enter the building you have lost control over your
life until you leave you are on somebody elses schedule. It will
involve a lot of waiting, and there is nothing you can do about it:

<ul>
<li>Waiting at reception to go to the waiting area for day surgery.
<li>Waiting at the waiting area for day surgery to go to the beds at day surgery.
<li>Waiting at the beds at day surgery to go to the pre-operation room.
<li>Waiting at the pre-operation room to go to the operation waiting room.
<li>Waiting at the operation waiting room to go into the operation room.
<li>No waiting here, because this operation room is expensive!
<li>Waiting at the operation room to go into the recovery room.
<li>Waiting at the recovery room to go to the day surgery.
<li>Waiting at the day surgery to get out.
</ul>

</p><p>
Before you get in the operation room, you will be asked the same
question every time: Your name, date of birth, name of the doctor
and what they are going to do on you. Just to make sure they have
the right guy in front of them.

</p><p>
The procedure done on my finger was over in 20 minutes. The anastetic
I got was a finger block, two needles in my hand which neutralized
all feeling in the ring finger, and some drowsiness stuff which I
think didn't really work at all. During the operation I could hear
the drill, but not feel the things they did on my finger.

</p><p>
At 14:30, after the operation and when I was out of bed, I was given
an arm sling to keep my hand up and a prescription for painkillers.
Six hours real-time for a 20 minutes procedure, it's very low
duty-cycle.

</p><p>
<a href="/weblog/images/IMG_1643.JPG"><img src="/weblog/images/IMG_1643-small.JPG"></a>
The finger itself now has a splint at the top of the hand and a lot
of bandage around it. You can see the wire sticking out at the top
of my finger, which is right now not scary yet...

</p><p>
I was told to take the painkillers when my fingers started to tingle,
which was a couple of hours later. Since the pain didn't come back
after that, I didn't take anymore and slept through the night. 

</p><p>
So is there pain? Yes and no.

</p><p>
There is irritated skin (for lack of a better description) around
where the wires are sticking out.  But there is no pain because of
the drilling, which can be either because there is no pain or because
the nerves in my pink and ring finger there are numb: For the last
four years I haven't had any feeling in them. I have seen a specialist
for it who has done the famous frog tests which will pull your
muscles when an electrical current is going through them and they
didn't find anything wrong with the nerves there.

</p><p>
Maybe that has gotten me through the night without painkillers,
maybe there was no pain to start with...

</p><p>
On Monday I have my first physiotherapy at 08:00.

</p>]]></description>
<guid isPermaLink = "false">00333@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00333.html</link>
<category>My mallet finger</category>

<dc:date>2011-06-15T16:00:00+10:00</dc:date>
</item>
<item>
<title>My mallet finger - Thursday 9 June 2011</title>
<description><![CDATA[
<p>
We went to see the hand-surgeon. From the X-rays he saw that the
break was at a nasty location: it was broken of in the contact area
of the joint. First a proper cast instead if the splint and then
new X-rays in case the piece of bone was put back in place by the
cast: it wasn't.

</p><p>
So the next options were: leave it like this and it will be half-fine
or have an operation and it will be fully fine. There are two kind
of operations which he could do: a screw with which the broken piece
get puts back or a two-wire approach with which the broken piece
gets pushed against the bone and regrows that way. Because of the
size of the piece broken off we chose for the wire.

</p><p>
After the operation I will have two pieces of wire sticking out of
my finger for four to six weeks, but they are luckily under a
dressing, and have a cask for that period too. After that everything
should be back in volleyball-playing-condition again!

<br>
<a href="/weblog/images/small cast.jpg"><img src="/weblog/images/small cast - small.jpg"></a>
<a href="/weblog/images/xray - 2.jpg"><img src="/weblog/images/xray - 2 - small.jpg"></a>

</p><p>
Next update: Coming Wednesday most likely.

</p>]]></description>
<guid isPermaLink = "false">00332@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00332.html</link>
<category>My mallet finger</category>

<dc:date>2011-06-09T16:00:00+10:00</dc:date>
</item>
<item>
<title>My mallet finger - Tuesday 7 June 2011</title>
<description><![CDATA[
<p>
A normal Tuesday: wake up, train, work, train, dinner, volleyball.
And then hospital, because my lefthand ring-finger got damaged
during the volleyball game.

</p><p>
When the finger got hurt, by a bad catch of a badly placed ball,
it didn't seem too much. About half a second later I was off the
field to get some ice for it.

</p><p>
The people from the Menai Sports center have a great solution for
providing cold-packs for injured players: just use a bag of frozen
peas, it works as well and doesn't cost as much if never returned.

</p><p>
The "let's see if thus goes over after ten minutes" approach worked
fine, except that I nearly fainted after the ten minutes when the
finger got bent. And there was a strange hump of the top of the
finger. Plan B, off to the hospital.

</p><p>
In the Emergency department you get first investigated by the triage
nurse (m/f for the Dutch people who have a different word for a
male and female nurse). He wisely didn't touch the finger and wanted
to make an X-ray first.

</p><p>
The X-ray departments these days don't work with photographic paper
anymore, the receiver is a kind of flat CCD device which wirelessly
transfers the image to the image library. Welcome to the 21st
century, goodbye to the "clunk clunk" sound of the replacement of
the film.

</p><p>
It showed that there was a little triangle of bone broken off and
I was told that the tendon was still attached to the piece. That
was the reason why it a. Hurt so much when trying to stretch the
finger and b. The finger didn't get stretched anymore.

</p><p>
The doctor could tell me that it was called a "mallet finger" and
that it was a common breakage for people who play ball-sports. I
still don't know the dutch name for it, maybe it only happens in
English speaking countries! The doctor knew so much about it because
he had had the same injury from the same sport earlier in life. And
his finger was close to back to normal and he played volleyball
again, so there is hope!

</p><p>
Later in the hospital I got a mega-splint on it and the message for
the hand-surgeon, including a CDROM with a JPEG and an uncompressed
picture of the X-ray, and I went home.

<br>
<a href="/weblog/images/hospital stint.jpg"><img src="/weblog/images/hospital stint - small.jpg"></a>
<a href="/weblog/images/xray - 1.jpg"><img src="/weblog/images/xray - 1 - small.jpg"></a>

</p>]]></description>
<guid isPermaLink = "false">00331@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00331.html</link>
<category>My mallet finger</category>

<dc:date>2011-06-07T23:59:00+10:00</dc:date>
</item>
<item>
<title>A proper WAN Optimization analogy</title>
<description><![CDATA[
<p>
Even after working for Riverbed Technology for two and a half years
now, I still have to come up with a bullet-proof analogy of how WAN
optimization works.

</p><p>
Consider a network from one side of this planet to the other side:
A round trip time of 300 milliseconds for 20 million meters.  Of
that 300 milliseconds, you have two factors: The speed of light to
get from A to B, and serialization delay which happens at every
hop and is related to the bandwidth and the size of the packet. One
is constant, the other one is variable.

</p><p>
To move data in a stream, the throughput is limited to the smallest
bandwidth in the path. Although you can move data faster on other
parts, it all has to go through this one.

</p><p>
As an example, say you have a stream of 300 Mb and a smallest
bandwidth of 2 Mbps. Without any protocol overhead, this will take
20 minutes to go through there. With a fourty byte protocol overhead
and an MTU size of 1500, this will take 20 minutes and 33 seconds.


</p><p>
Now with WAN optimization. It consists of three parts: Optimization
on TCP level, which has been ignored for now. Latency optimization
on application specific protocols, which has been ignored for now.
And data optimization, where the data is either compressed or only
referred to. If the same or similar data gets transfered via two
WAN optimizers twice, the first time you would get a relative small
reduction factor, depending on the compressability of the data,
while the second time you would get a large reduction factor because
the data patterns is alreayd known on both devices.

</p><p>
If that 300 Mb is split into segments of 1024 bytes, making it 300
000 segments, and each segment has a 64 byte label, you end up with
only about 19 Mb worth of labels.


</p><p>
Transfering that 19 Mb through a 2 Mbps link will be take 80 seconds,
about 15 times faster.


</p><p>
Now back to the topic: A good analogy for WAN optimization.


</p><p>
Is it faster than light? It feels like it, but the Round Trip Time
of the WAN is still the same. And the speed the packets go via is
still the same.

</p><p>
Is it a "wormhole"? Wormhole-based paths which are shorter than a
non-wormhole-based paths. The path travelled travelled for optimized
traffic still has the same distance.

</p><p>
Is it comparable with ships, where goods are stored in containers
(labels) and then transported in large bulk carriers? If the speed
limit of other ships was limited to the speed limit of the bulk
carriers, then it would be a good start.

</p><p>
Is it a train analogy, where passengers are cramped into carriages
and efficiently transported across the rail network? It could be,
except that on the railroad network everything is put into train
carriages and transported efficiently on it. Comparing it with the
French TGV and the Japanese bullet trains does not work neither,
because the speed of the packets is still the same while these
trains are way fast.

</p><p>
So, the analogy needs to use the same speed limits on the transport
mechanism, and needs to give the impression that the delivery gets
faster without changing the distance.

</p><p>
The best thing I come up with is transport of goods via large trucks
instead of via small delivery vans: Goods are shipped via small
delivery vans to a distribution point, stored into a single large
truck which then uses the same transport infrastructure as small
fast vans would have used if they would have transported their
payload. Instead of a long convoy of small vans, you get one truck
towards the distribution point which there gets reloaded into
numerous small vans. The only thing which does not make sense yet
is that small delivery vans are often 2 x 4 x 1.5 meters and big
trucks are 3 x rather long x rather high, which gives the impression
that size still matters while this isn't the case on WAN optimized
traffic...

</p><p>
That is the problem if you work with magic :-)
</p>]]></description>
<guid isPermaLink = "false">00330@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00330.html</link>
<category>Networking</category><category>Riverbed</category>

<dc:date>2011-03-29T18:00:00+10:00</dc:date>
</item>
<item>
<title>All about MAC addresses</title>
<description><![CDATA[
<p>
The "FreeBSD laptop as a Wireless Access Point for an iPhone" project
I wrote earlier about has made me some followers, mostly they have
no idea where the free internet connection comes from.  But, based
on the amount of download measured on it, they are enjoying it. One
of the methods to determine how many people are on it is to use the
output of the "arp -na" command: Every MAC address you see there
is a mobile device which is associated with the wireless access-point
you created.

</p><p>
One thing which you can do with that data is to match it against
manufacturers. Very boring for non-networking techies... Don't read
the rest :-)

</p><p>
MAC addresses consist of 12 hex-digits (48 bits) which are split in
two parts: A six hex-digit (24 bits) prefix and a six hex-digit
sequence number.

</p><p>
The MAC (or OUI as the IEEE calls it) prefix database can be found
on the website of the IEEE at
http://standards.ieee.org/regauth/oui/oui.txt. It contains at the
moment of writing 14765 prefixes. The manuf(acturers) file from the
Wireshark project can be found at
http://anonsvn.wireshark.org/wireshark/trunk/manuf and contains
18321 prefixes plus a handful of shared prefixes.

</p><p>
Why is the one from the Wireshark project larger? Not really sure,
but if you look at the registration costs it (US$ 1750 for a public
registrered prefix OR US$ 1750 plus US$ 2100 per year for a private
registered prefix) must be part of it. So it could be that the list
from the Wireshark project has determined a bunch of the private
ones. And unlike IP space which you can register in advance, you
can't get a new prefix until you have certificated that you have
used 95% of the sequence numbers.

</p><p>
Some statistics based on grep and cut and wc:

</p><p>
<blockquote><pre>
 Number of prefixes	Company
		503	Cisco
		122	Shenzhen
		112	Motorola
		109	Nokia Danmark A/S
		84	Samsung Electronics
		84	Apple
		78	Intel Corp
		59	Advanced (??)
		61	Hewlett Packard
		51	Private
</pre></blockquote>

</p><p>
"Advanced" could be a mistake in here, since it matches Advanced
This and Advanced That. "Private" means a company who pays the US$
2100 per year. Shenzhen has the same issue as "Advanced", it is a
large bunch of companies in the Shenzhen city in China (near
Hongkong).  Apple was the company I didn't expect in the Top 10,
but considering their iPhone / iPad success, it shouldn't surprise
much.

</p><p>
Every prefix has 2 ** 24 entries in it, or 16 777 216 (about 16
million if you are conservate, or 17 million if you are optimistic),
making there 1.4 billion Apple MAC addresses in the world. That
number is not the number of Apple devices, since you need one per
network interface: Ethernet, wireless or Bluetooth.

</p><p>
But the other number of Cisco is much more impressive: 8 438 939
648 MAC addresses. More than the next five in the list together.

</p><p>
Unfortunately the list of prefixes does not contain any assignment
dates, it would have been interested to see what happened when LANs
based on switching instead of hubs became the norm (and thus Cisco
when Cisco started to sell their switches) and when mobile devices
like the iPhone became popular, it would have boosted the allocation
rate by Apple for sure.


</p><p>
MAC prefix exhaustion?

</p><p>
Unlike other technologies, and IPv4 comes in mind here, the MAC
address prefix pool is pretty much unlimited but also only slowly
being touched: There are 2 ** 22 or 4 194 304 prefixes. The number
is 22, not 24 because two bits in the first byte of the prefix are
used to determine if the MAC address is globally unique one or a
special one. And right now, a good 35 years after the invention of
Ethernet and Tokenring there are not even 19 thousand used.

</p><p>
The other causes are of the more strict rules the IEEE handles: You
get a single prefix and don't get more until you have informed us
officially that you have used 95% of them, and of course that you
actually need to produce (and sell) something which uses a MAC
address.

</p>]]></description>
<guid isPermaLink = "false">00329@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00329.html</link>
<category>Networking</category><category>Apple</category><category>Cisco</category>

<dc:date>2011-03-17T18:00:00+10:00</dc:date>
</item>
<item>
<title>Online newspapers, waiting on the iPhone to load them</title>
<description><![CDATA[<p>
One of the uses of my iPhone is as a replacement for the newspapers
and other news sources. Yes, I can do this on the computer too, so
far nothing new. The thing which fascinates me is how much time I
spend on waiting for the data to be retrieved.

</p><p>
Take the ABC app. On it, I only read two sections: The Just In
section and The Drum. I open the app, have to wait for the Latest
News section (which is not the Just In section) has been loaded,
then I tap for the overview of the sections (which is instantly)
and then tap on the Just In section, for which the overview gets
loaded. To read an article, I tap on that article which then gets
loaded. So I have to wait three times before I can read a single
article, and every other article I need to wait again. Even after
having read the ABC news this way for about a good year now, it
still doesn't remember which news sections I'm interested in and
doesn't pre-load them.

</p><p>
Take the SMH app. It is a little bit nicer, you can tell it which
sections you are interested in and only shows those. It opens the
one you opened last time up first. Could be close to a winner!  But
then it has the same cons as the ABC app: It loads the index and
when you tap on the article you want to read it loads that one.
Waiting twice again.

</p><p>
Take the Volkskrant app. It has two major sections, the Just In
section and the Opinion section. When you start the app, the index
of the Just In section gets loaded together with the text of all
the articles. When you tap on an article, it comes up immediately
and then loads any images: You can read it immediately. So you only
wait once.

</p><p>
Take the BBC app. Just like the Volkskrant app, it loads the index
and contents of the main sections at startup, which also has a lot
of images on it. When the article gets loaded, it will load the
image on the article.


</p><p>
The method of loading of content done by the BBC app and the
Volkskrant app is by far the most ideal way of using an online news
app. I am not yet sure if I prefer the sober layout of the Volkskrant
or the smooth horizontal scrolling layout of the BBC.  But overall,
I am looking forward to the day the Australian news apps have caught
up!

</p>]]></description>
<guid isPermaLink = "false">00328@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00328.html</link>
<category>Mass Media</category><category>iPhone</category>

<dc:date>2011-03-02T18:00:00+10:00</dc:date>
</item>
<item>
<title>Volleyball, summer competition 2010/2011</title>
<description><![CDATA[<p>
Despite the serious losses our team had in the previous Winter 2010
competition, for example the zero won games and thus being ranked
last, I decided to go continue in the Summer 2010/2011 competition.
Minor detail: Nobody from the old group kept playing. Luckely we
got a new team together.

</p><p>
This season wasn't as bad as the previous one despite that we still
ended up second last: We won two games.

</p><p>
Our new team has a good players, we just don't work together or
take the basic rules into account. Too many times the ball just
gets slammed into our side of the net, too many times we don't setup
properly, and too many times we lose the ball because we don't take
a step to the left or right to properly catch and play the ball.

</p><p>
For the next competition, how to can explain these issues to the
members of my team without upsetting him or her and everybody else?
Maybe I should just do it and see what happens...

</p>
]]></description>
<guid isPermaLink = "false">00326@http://www.mavetju.org/weblog/</guid>
<link>http://www.mavetju.org/weblog/html/00326.html</link>
<category>Sports</category><category>Volleyball</category>

<dc:date>2011-02-28T18:00:00+10:00</dc:date>
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