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Hi, I'm Iljitsch van Beijnum, writer, freelance network engineer and PhD student. I'm from The Hague. Some of the blog posts here are in Dutch, others are in English. See for just work-related posts.

Skating with my Fothon illuminated wheels

Despite the blister on my foot I couldn't resist going out and trying out my new Powerslide Fothon wheels for my inline skates. I got a 4-pack of wheels with red LEDs:

The wheels contain a small generator that uses the rotation of the wheel to generate electricity for the LEDs, so they come on when the wheels turn. Because all of this slows down the wheels a bit, I'm only using one on each skate. They also come in white, blue and green.

And as always, iPhone slow motion video for the win!

Permalink - posted 2015-07-03

Yay, nectarines are back in season!

Yay, nectarines are back in season!

Image link - posted 2015-06-17

IPv6 is faster than IPv4 on US mobile networks

At the NANOG meeting in San Francisco two weeks ago, there was a session on The benefits of deploying IPv6 only. Someone from T-Mobile explained that the latest Windows Mobile and Android support 464XLAT to allow IPv4-only applications to work over IPv6 with NAT64, so those devices now only get IPv6. Other devices only get IPv4, there's no dual stack. At that point, the panelists didn't know yet that Apple is requiring iOS 9 apps to work over IPv6 so those can work through NAT64 without 464XLAT.

Another interesting data point is the observation by Facebook that IPv6 tends to perform better than IPv4, with the margin being as large as 40%:

However, why this is is unclear: the RTTs are the same, yet the performance/bandwidth over IPv6 is better. There was some frustration because Apple's implementation of "happy eyeballs" only looks at the RTT to choose between IPv4 and IPv6, and thus lands on IPv4 a good deal of the time and doesn't enjoy the benefits of that better IPv6 performance.

Permalink - posted 2015-06-17

→ Apple to iOS devs: IPv6-only cell service is coming soon, get your apps ready

During last week's WWDC, Apple announced that it will start requiring iOS 9 apps to support IPv6. The reason for this is that cell carriers want to move from dual stack to IPv6-only cellular data service, with NAT64 to let users reach IPv4 destinations. This only works if apps use IPv6-compatible APIs and don't do things like checking for the availability of (IPv4) internet connectivity or using IPv4 addresses directly, rather than DNS names.

The article links to a WWDC video that explains all of this in detail, and then continues with some other very interesting information on network performance issues, including the fact that Apple is turning on Explicit Congestion Notification (ECN) in the new versions of MacOS and iOS. Microsoft tried to do the same thing in Vista, but had to turn it back off because too many firewalls blocked packets with ECN. Hopefully that's no longer an issue seven years later.

Read the article - posted 2015-06-16

Customize Safari Reader font

I think yesterday's WWDC was the longest one I've seen at nearly 2.5 hours. Still, there wasn't much to get excited about. Apple Pay is coming to the UK, but not to the rest of the world. Apple Maps transit directions are coming to two handfuls of cities and all of China, but not to Holland. Apple's new news app is also limited to the US, the UK and Australia. The music stuff may or may not be interesting, but I'm afraid it's going to get in the way of simply playing the music I have on my computer and my iPhone.

But... reading the fine print, there is one thing I can get behind:

A customizable font for Safari Reader!

I must be getting old, but I really can't stand what the web has become these days. The trend to have fixed banners at the top and/or bottom of pages gets on my nerves, because that way you can't scroll a webpage one screen at a time. It's also visually distracting. As are the attention-grabbing ads, which are often animated or video. So there's hardly any text I read on the web without invoking Safari Reader.

However, Safari Reader itself isn't all that great: the width of the text is fixed, so in order to get avoid having too many words per line, which makes it hard to land on the next line, I need to keep the text size bigger than I'd like. (Funny, because 95% of web pages use text that is way too small.)

Safari Reader uses the Georgia font, which isn't terrible, but largish serif fonts just don't take advantage of high resolution displays. So I hope that in addition to the ability to configure a nice sans serif font, we also get to adjust the margins in Safari Reader.

Permalink - posted 2015-06-09

DAB: mijn eerste digitale radio

Alles in het leven is tegenwoordig digitaal, maar de radio is eigenlijk niet veranderd sinds de invoering van FM in de jaren '50. Maar als we dit promotiefilmpje van een jaar geleden mogen geloven is de radio nu ook hard op weg om digitaal te worden! Dat wilde ik zelf wel eens horen, dus gister heb ik mijn eerste digitale radio gekocht.

Volledig artikel / permalink - geplaatst 2015-06-04

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