I value my privacy and have no intention to put apps on my devices whose first act is to scrape my phone book. That’s why I’m a heavy user of ‘Conversations‘, an open source mobile chat app for Android with end-to-end encryption. Unfortunately, Conversations is only available for Android. There are some iOS Jabber apps available as well but I always found them lacking in one way or the other and could thus not recommend them to iPhone users. Until now!
Author: Martin
Gogo Inflight Traffic Shapping
When I recently flew from Europe to the US with Delta Airlines I was quite positively surprised about the Internet access that was offered on board. Over recent years, I noticed that Internet connectivity in the air significantly slowed down to a point where it is almost unusable. On this flight however, I could browse the Internet just fine and get a lot of stuff done for which I needed to be online. However, I noticed an interesting traffic shaping method that made downloading larger files impossible.
Building a Cray Y-MP (Model) at Congress
When you spend 16 hours a day at Congress, there is some time to do things that one otherwise would not come around to do. For 35c3, I took a model kit of a Cray Y-MP with me to assemble that has space for a Raspberry Pi Zero in its center cabinet. A bit of time and half a gram of super glue later and I had the perfect combination of what once was the fastest and one of the most expensive computers in the world in the 1980s and one of the smallest and cheapest computers running Linux in 2018.
Chasing Seymour, Supercomputing And Punchcards
Back in November last year I wrote about ‘The Supermen‘, the story of Seymour Cray and the birth of supercomputing and mused about my personal reasons to learn about this particular piece of computing history. Reading about something is one thing, getting hands-on experience with technology from the 1960s quite another. Not possible you say?
Continue reading Chasing Seymour, Supercomputing And Punchcards
NB-IoT – From Theory To Practice – Part 2
In the previous post I had a lot at how I can get my newly acquired NB-IoT module connect to the network. This is part two that now focuses on how to actually send some data back and forth across the NB-IoT network to a server on the Internet.
NB-IoT From Theory To Practice
Back in 2016 and 2017 I had quite a number of articles on NB-IoT, the Narrow Band Internet of Things technology that can run alongside LTE to connect things to the Internet over the cellular network. From being very power efficient to run over years on batteries to increased in-house coverage, the standard contains a lot of bells and whistles to address a wide variety of use cases. While I believe that ‘connecting things’ is the next big thing after mobilizing the Internet, it’s been very slow in the making, at least when it comes to cellular connectivity. I would have been quite keen to experiment with NB-IoT but up to now I didn’t come across devices and SIM cards that could be bought that would support it. Until a few days ago that was when I discovered an NB-IoT module for the Raspberry Pi on Amazon so it was finally time to go from theory to practice on the technology.
Booting With UEFI
One of the technology mysteries most people don’t really want to spend a second thought on is how the operating system of a PC is booted. When installing Linux next to Windows on the same disk, however, or when you plan to move a disk from one PC to another at some point, or when you want to restore a system image from a backup, it’s worth to understand at least the basics of the process to fix things in case something goes wrong. In a recent edition of the c’t magazine (see here, in German, article behind a paywall) there have been a number of great articles about the topic and here are my takeaways that will help me in the future.
5G Auctions – Let’s Look Back to 1989
There is a lot of media attention in Germany on the upcoming spectrum auction for 5G that is scheduled for early 2019. Like in previous rounds, spectrum is awarded via an auction to the highest bidders. Someone recently asked me if spectrum has always been auctioned so I had a look in my archive to find some details from days long gone.
Javascript Debugging on the Tablet
Unknown to most people, web browsers such as Firefox have a sophisticated debugger built-in to look at everything from page load timings to HTTP header contents and Javascript debugging. For web developers this is a great help on the PC. Recently, I had to debug a web application that worked all right on the PC but wouldn’t quite work as intended when used on a tablet. So what’s the approach for debugging a web app on smartphones and tablets? I turns out that Firefox on Android on the PC have powerful ‘remote over Wifi’ debugging capabilities that are surprisingly simple to use.
Things That Moved Me in 2018 – Part 2
And off we go straight into part two of my summary of things that moved me in 2018!:
Raising My Shields – Year 5
Ever since the Snowden revelations in 2013 I’ve been moving more and more services I use into my own domain and made sure as much of my Internet traffic as possible is encrypted. In 2018, I’ve made a number of significant improvements. First and foremost, Nextcloud Talk has become available and I’ve been using it since its launch for end to end encrypted and self-hosted voice and video calling. While it still continues to evolve for a more ubiquitous use from mobile devices, I used it a lot for voice and video calling from PCs in 2018.
Another weak point in my communication infrastructure has been internal email. While I made sure communication encrypted between clients and the external server, emails were obviously unencrypted while on the external server. So this year I took some time to finally put an email server in place at home for family internal emails that contain things that really shouldn’t be stored outside our domain of influence.