Unexpected benefits of IPv6 tunnelling

by Oliver on Thursday, December 26th, 2013.

Recently I wrote about getting my IPv6 tunnel setup working properly again after a while of it not working very well (or not at all). Since my ISP doesn’t yet (to my knowledge) provide native IPv6 connectivity to regular consumers, I tunnel IPv6 via Hurricane Electric, which on the whole works pretty well.

Another fantastic thing that my ISP does is throttle YouTube (and presumably other) traffic, which can make it unusable at the best of times, even at the lowest resolutions. I’m being sarcastic, obviously – it’s REALLY irritating. YouTube, GMail and presumably many other Google services as well as other mainstream sites such as Facebook have supported IPv6 for some time by default and the range of sites supporting it is fortunately increasing (although not nearly fast enough). After getting my IPv6 running properly again, I noticed that YouTube videos were actually starting quite fast and playing back without interruption.

Presumably Deutsche Telekom is doing some fairly basic packet inspection or identification of YouTube flows based on Autonomous System numbers or known IP subnets, as the tunnelled traffic via IPv6 is not throttled it would seem. Despite being re-routed via Frankfurt and suffering a small additional latency penalty, I still get vastly superior YouTube performance over the IPv6 tunnel as opposed to regular IPv4 transit. Especially given that the much smaller IPv6 routing table is often not nearly as optimised as the vast number of IPv4 routes, this is pretty impressive.

So in actual fact I’m currently better off with my tunnelled IPv6 connectivity than having native IPv6 connectivity through Deutsche Telekom. Odd, but currently very satifying.

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Thursday, December 26th, 2013 Germany, Tech No Comments

Too much to do, too many first world problems…

by Oliver on Saturday, September 14th, 2013.

We’ve been in the country for almost four years and I still feel like I don’t have a very good grasp on the language. OK, there are indisputable differences between children and adults in language learning but that doesn’t mean you can’t learn a language in adult life. I just find that I procrastinate, and find it hard to prioritise the language learning into my daily routine.

Sometimes it is just easier to zone out and read 9gag, or Failblog. I’ve cut down my RSS subscriptions to the point where I get through them all in a few minutes every couple of days. There is a constant few technical papers or videos I have on the backlog to read or watch when I get a moment, and sometimes actually get to them. I’m progressing rather slowly with Seven Languages in Seven Weeks, a book about learning seven computer languages – and I’ve almost completed the 5th in the list but haven’t yet managed to prioritise even my first non-native spoken language – German.

At work we recently did a “Bio Hacking” course, which sounds a bit hand-wavy, but at its core was basically about getting your stress levels down and allowing your brain the rest periods necessary to operate it at full capacity. I also learned that procrastination (among other things I learned about my habits) is related to an over-developer aversion to failure. Probably learned during childhood through some catastrophic failure event, or alternatively so much success that you couldn’t bear the thought of not succeeding. I’m not sure I recall either of these happening so it’s a bit of a mystery to me.

Nevertheless I am procrastinating right now in writing this blog post instead of finishing the chapter on Erlang, or doing some German revision. It’s hard to think I’ll change my habits drastically after 34 years on this planet, but I also can’t stand the idea of becoming one of those people who has stayed in Germany for 10 years and just gave up learning the native language at some point. Or really anybody that just gave up trying to better themselves at any point in their lives because they saw it as futile.

Saturday, September 14th, 2013 Germany, Thoughts No Comments

Bike upgrade

by Oliver on Saturday, September 3rd, 2011.

I’ve had a cheap, crappy bike for a while now and so far it has served me fairly well. It is not in great condition and has its problems but generally works despite my recent fitness kick which has seen me taking my son out for morning rides before work in the trailer which hangs off the rear axle. The additional weight of course puts a strain on the axle and gears (not to mention ME) and the already warped gears and chainrings started to complain about it. The chain started skipping off the rear sprockets more and more regularly despite my efforts to adjust the rear derailleur.

So, never the one to shy away from a bit of do-it-yourself modification work I decided to investigate replacing the gears. Berlin is fairly flat and with three front chainrings and seven sprockets on the rear cassette I was amply supplied with gear overkill. I had looked into the Shimano Nexus internal hub series and the Nexus3 had taken my fancy so I ordered what I thought were the parts I required from a shop selling their stuff on Ebay, and began the process.

Above you can see basically what I had to deal with (prior to realising that taking the bike apart inside was a bad idea, not only for the mess but because of my toddler running up and grabbing greasy parts). It’s a pretty standard Herrenrad made by Kreidler. First up I just had to remove the rear wheel and all unnecessary bits. This amounted to:

  • Removing the chain, which is made pretty easy by the derailleur.
  • Removing the rear derailleur which just requires one hex bolt to be taken out.
  • Removing the nuts and washers securing the rear wheel.
  • Loosening the rear brakes. There is a shortcut here which I didn’t realise before – you can just slide the “spaghetti” tube out of one side of the brakes to loosen them completely. I’d been loosening the cable instead all the previous times.
  • Cutting the unneeded shifter cable to the back derailleur and removing related garbage.
  • Removing the front derailleur, cabling etc as well since I was only going to use a single chain-ring up front after the modification.
  • Removing the actual rear wheel.

Here you can see the new wheel slotted into the dropouts. The three gear internal hub is surprisingly small compared to some of the seven and eight gear beasts out there. This is more or less all I had after I initially ordered parts. Actually, to be precise I had:

  • Rear wheel with internal gear hub.
  • Shifter mechanism, cable and attachment to hub
  • Chain tool

Shortly after these parts arrived I realised I was missing most of the rest of the rear wheel assembly, most noticeably the sprocket.

So I ordered that part as well from the same place, hoping that was all I needed. Not so. There are a bunch of other washers, rings, fasteners and the funny little pin that goes into the hub as part of the shifting mechanism which you can see sticking out in the photo above. Apparently there is a kit that contains all of these additional parts (Schaltungszubehör) but I could not source it easily here, nor did any of the shops I visited have it.

By the time I had taken the above picture I had received parts ordered from two stores on Ebay, some of the accessories from a bike shop on Prenzlauer Allee (after fruitlessly checking two other local shops) and a new tyre and inner tube from Stadler (an absolutely massive bike shop just next to Storkower Straße S-Bahn). I also had an incorrect accessories bag which suits an SRAM seven gear internal hub. Huzzah!

I’ve tried to take a frugal approach to this bike wherever possible, applying the “if it ain’t broke don’t fix it” mentality reasonably successfully. So I was slightly torn when I was getting the rear sprocket properly attached at bike shop #3 and the guy asked if I needed a chain. I initially said no, then decided I should get a new one in case the old one was too stretched. As you can see, the old one is completely the incorrect type for the new sprocket so it would have been a total failure and required yet another trip out for the chain.

A word of caution – don’t perform bike surgery over an open drain outside. My first snap lock chain link dropped out of my fingers and into the drain below almost immediately and I was forced to make a stop at bike shop #5 right before it closed on a Saturday (and none are open on Sundays). Aside from that, these links are invaluable if you need to mess about with your chain, while finding the best length. Take it slowly and don’t remove too many links at once! Test before taking out more, as it is almost impossible to reattach links using the regular tool.

Here are the bad boy front chainrings. The initial plan was to use the largest (which I believe was something like 42 teeth), although the angle from it to the rear sprocket was significant and I wasn’t interested in doing funny chainring surgery to reduce the angle.

After the initial chain shortening and connection, here is the first working example of the drive train post-modification.

The shifter was pretty easy to install and fit in reasonably well with the existing half-length handlebar grip, although it is a little short now. The exit point of the cable is also a bit irritating as it gets in the way of the bell. But it works.

Here is my ghetto shifter cable installation with synthetic string. Hey, it was only temporary.

Shortly after putting the bike back together, I took it for a test ride and the chain slipped off almost immediately after putting a bit of load on it. I assumed that the problem was the angle between the front chainring and rear sprocket so I moved the chain to the middle chainring and shortened it again. This seemed to fix the problem at least for just myself riding the bike at reasonable speeds and in all three gears.

Here is a different view of the rear hub and shifter mechanism attached. It just houses a small lever that is pushed and pulled by the shifter cable. In turn, it pushes on the pin that goes into the hub and causes the gear changes in three different pin positions (depths).

After taking the bike for a real ride with trailer attached, the chain got progressively looser and looser until it started skipping, and by only 5km I was getting rather nervous about it. I turned back but by 9km it jumped off and I had to coast home. The axle on the chain side had obviously moved out of the dropout slighltly, so I had either under-tightened the nuts or not had enough locking washers or nuts or both. I also suspected the front chainrings to be slightly warped (as the rear cassette had been before) which didn’t help.

At this stage I had not been able to ride for about two weeks so I had run out of patience. I took the bike to my local shop (literally 100m away) and asked them to fix whatever was wrong. They tightened up the axle and replaced the front chainrings with what you see pictured, a single 38 tooth ring and new crank arms. As a bonus whatever they did fixed the noisy bearings in bottom bracket and my pedals don’t wobble about as they used to.

The end result was extremely good. The combination of 38 teeth in front and 16 in rear give me a very good set of ratios between the three gears – 48.7, 66.5 and 90.7 gear inches respectively. Even with the trailer they work very well for the local terrain. I would not do it the same way again but I don’t regret anything about the upgrade.

For any budding bike DIYers out there I would suggest a few things if you are contemplating this:

  • Before you do anything, read Sheldon Brown’s excellent site.
  • Find the most well-stocked bike shop in your city and go there. Tell them what you want to do to your bike and just get them to supply all the required parts in one hit. It is much better than having to find out for yourself that you are missing one obscure part that nobody carries.
  • Get the right tools to do the job, and make sure they are high quality (this goes for just about anything mechanical).
  • Pester your friends with bicycle repair knowledge and mine it.
  • Allow plenty of time! If you will go crazy if you can’t ride for more than a couple of days, make doubly sure you can get it all done, or you have a rollback plan (or better yet, another bike).

If you have done similar upgrades, please leave a comment as I’d love to know what you did and how you got on.

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Saturday, September 3rd, 2011 Germany 2 Comments

Preparing (slowly) for Winter

by Oliver on Saturday, November 13th, 2010.

Last year in Berlin we had a fairly terrible Winter, with temperatures going down to -30C which we were completely unprepared for. Ange was pregnant and neither of us had really adequate clothing although we both got sturdy boots and some thermals to stop from freezing altogether. This year we vowed to be more prepared, and one of the most popular brands that we see on the streets is Jack Wolfskin. Yes, it is a “name brand” and I think a lot of people just wear it for the logo rather than the quality.

However, they do actually make some pretty good stuff. I picked up a pair of gloves to stop my hands from freezing on the ride to and from work and they keep my hands nice and toasty the whole journey. I don’t expect that we’ll become as bad as some of the people out there (I’ve heard of entire families getting around entirely clad in JW gear) but I think we’ll look into some other items to keep the cold out properly this winter.

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Saturday, November 13th, 2010 Germany No Comments

Devopsdays 2010

by Oliver on Friday, October 15th, 2010.

I’m in Hamburg! If you’ve read through my previous articles I’ve written for Anchor you would know that I love going to tech conferences. I’m currently at Devopsdays which is being hosted in the very stylish East Hotel, just down the road from Hamburg’s red-light district. I haven’t actually been outside during the day yet since we caught the EC train up from Berlin last night, but I’m enjoying the conference so far.

We’re trying to implement a Devops culture at work, which so far has just resulted in a lot more work as the initial chaos subsides somewhat but I’m always cautiously optimistic about these things. In stark contrast to the Linux Conf AU conferences I’ve been to (3 so far, but I missed the last one sadly) there is definitely a sense of this conference being in its infancy. There is a lot of excitement about the potential of Devops, and a lot of people very interested in implementing it but not really sure how to. There seems to be only a few “experts” and many “novices” eager to learn, whereas LCA seems to be a more even mix (with the odd number of wizards thrown in too).

I actually managed to score my own Open Space session to talk about configuration file distribution issues which was informative, and confirmed I’m at least on the right track. On another note, if you’re looking for interesting work as a Developer or Sysadmin in our Devops team ( ūüėČ ) Nokia is hiring in Berlin!

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Friday, October 15th, 2010 Germany, Tech No Comments

oh the places you will go…

by Angela on Tuesday, September 28th, 2010.

Recently Oliver and I met up with some friends who had exciting news to share. After years of corporate success in their various fields, (one friend is a solicitor, and the other is a software developer) they have decided to pack up their lives in Amsterdam where they are living Р quit their respective jobs, and go travelling around Europe, living in their camper-van for the next 18 months!

To me, that is an ultimate reality.  I have such high respect for them to make such a radical and exciting decision, to take control of their life.

It is also something I would love to be able to do with Kai before he starts school. I am not sure how long I would enjoy ¬†doing it “rough” in a camper van for two years, but I would try for the sake of the adventure. Seeing all of Europe, ¬†spontaneously¬†stopping in one place exploring, and then moving on when you were ready!

You have your essentials -your partner, warmth, shelter, a bed and shower, power and electricity for phones, and most camp sites have WiFi for catching up via the net.

Interesting how perspective works – When I told my gorgeous greek ¬†friend about how I wish I was embarking on such an adventure she replied ¬†–

” Ange, you ARE doing it. You are living in Berlin – ¬† the most¬†exciting¬†and dynamic European city. You have a wonderful partner, and together you are exploring Europe and raising your baby here…because you are here day to day, you do not realise that you are living that way;¬†you cannot have EVERYTHING”

and she is right

– ¬†Oli and I did just ¬†decide one day after much¬†deliberating¬†that we would just pack up and leave Sydney, quitting our jobs, selling all of our belongings and moving to Berlin with just one suitcase each. When we left we had no¬†apartment¬†or jobs waiting for us ¬†to go to, we knew no one in Berlin, ¬†we didnt speak fluent German, and I was¬†pregnant…

Since being here for almost 12 months, I have had lots of time to think about what it will mean for Kai¬†to be raised¬†“German”.

Im slowly but surely coming to terms with the fact that If Oliver and I choose to stay here in Berlin long term, ¬†then we will be sending Kai to school here. ¬†He will be raised without Oli’s or my extended family – ¬†his grandparents, aunties, uncles and cousins. I was raised in a big family and I have founding memories of large Christmas’s, Easter and family gatherings for birthdays, baby showers, Christenings or weddings. There is always way too much yummy food, lush home cooked smells, lots of laughter and¬†squeals¬†of delight from all the children.

Growing up with a strong family around me significantly influenced the woman I am today.

Don’t get me wrong, We have friends great here in Berlin, but it will not be the same as those family gatherings. Blood is always different. You choose your friends, but the family where I come from there is a special bond of support and¬†guidance, there is wisdom. You can ask things of family you cannot of friends. I am often hearing about how my sister can leave my nephew with my mum so she can have a break. That is something I will never have if I stay here.

I wonder if depriving Kai of that is too great a sacrifice.

Then there is all the things Kai stands to gain. I can provide for Kai what I never had, the opportunity to grow up bi-lingial, speaking two or ¬†more languages. The¬†accessibility¬†to all of the rest of Europe only an hour plane flight away. a fantastic education system, elite health-care,¬†fantastic¬†cultural¬†opportunities¬†– the art ¬†and music scene here is amazing. Really Oliver and I have only begun to scratch the surface of what Berlin has to offer us both individually and as a family….

The ease of travelling for us around Europe will mean that Kai will be meeting new people who can teach him things about the world that you cannot get from a book or the internet. Seeing parts of the globe that hold history, and are unique or one of a kind.

Talking to a friend who recently dropped in to Berlin made me realise that the arts in Australia is the same as before I left a year ago. She told me I made the right choice to leave. She is thinking of moving to Berlin herself- even though she is getting a lot of acting work, she is not satisfied. it is mainly commercials. Australia and Sydney is so small,  the arts community is select and funding is still so sparse that it is hard to develop new things. Theater is still so hard to develop, and it is usually the same old things that get produced.

If only I could have an express train to Sydney that would let me go see family and then return to Berlin… but like my friend says,
“You can’t have everything…”

can I???

Tuesday, September 28th, 2010 Germany 1 Comment

Winter’s on its way

by Oliver on Tuesday, September 28th, 2010.

This week has definitely been colder so far than last week, noticeably so. We’re getting down to ranges of something like 8 – 16 degrees Celsius, with gusty winds and rain. Of course, I love this kind of weather but it does necessitate certain precautions. Unfortunately I caught a cold last week from some scoundrel at the office and had to take three days off work, but fortunately I was more or less back in shape today, so it was back to my usual routine of cycling to and from work.

I own possibly the worst bicycle in Berlin that isn’t rusted and chained to a tree, one wheel kicked in and bent while the other is completely missing, seat long gone and handlebars soon to follow. Mine has a bit of rust, up until recently had only half a seat and will transfer buckets of oily grime to you at the slightest touch. With the wintery days approaching the days are growing shorter and darker; the threat of snow imminent on the horizon. It’s probably best if I take care of some of the minor safety issues now before it becomes too late.

Up first is the broken dynamo. It put up a good fight, but only really lasted a couple of weeks after acquiring the bicycle (and even then was only sporadically used, mainly out of curiosity). Off it comes! I didn’t realise this prior to removing it, but the top was completely wonky and broken.

About a month ago I discovered that a local hardware store, Obi, carries most if not all of the things I could possibly want for bike repair (this is after I bought a bunch of stuff off Ebay for probably about the same price they had them). So after having an Ebay seller not deliver the cheap dynamo I bought (I managed to get the money back from Paypal fortunately) I decided to check out their offerings in dynamos.

For the princely sum of ‚ā¨6 I picked up this little 6V 3W gem, and actually managed to fit it to the bike correctly first time, and wired it up ok. The lights work again (front and back) so my safety level has just gone up a few notches (and I do wear a helmet, unlike most locals).

Unfortunately, that’s about where this story ends. The rest of the bike is in pretty shabby condition: it only acquired a front mudguard quite recently, the chain tended to skip quite badly until I adjusted the rear derailleur but I still leave it in one gear most of the time and the brakes, while they do work, leave a bit to be desired.

Check out the tyres! Yes, that’s some quality right there. I was hoping to leave it on until it wore out completely, forcing me to buy a new one but it seems for the sake of safety I might have to change it early for a winter tyre, if such a thing exists for bicycles.

But hey, at least I can see in the dark now.

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Tuesday, September 28th, 2010 Germany No Comments