I really like the Raspberry Pi platform as it gives me full Linux flexibility for many of my projects. The platform’s limit, however, is networking, as a Pi only has a single 100BaseT Ethernet interface. Yes, it can be extended via additional USB/Ethernet interfaces and I’ve done so in the past but it’s a bit … Continue reading Routing With Linux At The Edge: The Ubiquiti ERX
Recently my firewall at home had a bit of a hick-up and decided to change the rule to forward a high external TCP port number to port 22 of one of my servers into a 1:1 mapping of that port instead. As I was about to go into a long meeting I couldn’t immediately react … Continue reading Port 22 Anecdotes
And finally, here’s part 3 of my series of entries on what moved me in 2016 technology wise. While part 1 and 2 focused on networks and Linux computing this part deal with a few miscellaneous things.
Apart from mobile networks, another topic that I write about quite often these days is Linux in general and Ubuntu in particular. Ever since I jumped into the Linux world in 2009 it’s been a thrilling and liberating experience and 2016 has been no different. So here’s part 2 of my summary of what moved … Continue reading Things That Moved Me In 2016 – Part 2: Linux
Like every year, time has flown and it is already end of December and thus time to look back at what has happened this year that has literally ‘moved’ me. This year I have three categories: Networks, Linux & General computing and Miscellaneous Other Things. Let’s start with a look back at my year in … Continue reading Things That Moved Me In 2016 – Part 1: Networks
In LTE, data is transferred over the air interface over ‘Default Bearers’ and ‘Dedicated Bearers’. The terms are a bit confusing but actually the concepts behind them can easily be explained: Virtual Network Interfaces and Traffic Shaping Rules.
Once upon a time a PC was connected with a cable to a network and usually had one IP address. The same applied to smartphones until a couple of years ago. But no more, most smartphones today have more than one IP address at a time, at least some of the time. Any idea how … Continue reading How Many Simultaneous IP Addresses Does Your Mobile Have?
In the previous blog post on VoLTE I discussed how speech codecs are negotiated during connection establishment. VoLTE uses the AMR and WB-AMR codecs that are adaptive and can encode the voice stream in several data rates and qualities. In the case of WB-AMR, voice streams can be sent with data rates between 6.6 and … Continue reading VoLTE – Some Thoughts On Bandwidth Negotiation
After moving from Typepad to my own WordPress installation, search engines haven’t yet caught up with the change. As a consequence most of the traffic is from regular readers who have updated their bookmarks and RSS feeds after reading about the move from the old site. So before traffic referred to my blog by search … Continue reading Blog Statistics – The First Weeks
Back in December 2015 I found my first public Wifi network at 32C3 that used a certificate instead of a common password, not so much for user authentication but for assigning an individual ciphering key to each device. Especially at a hacker conference that’s a plus as normal WPA encryption uses the same passphrase for … Continue reading Eduroam – Wifi With A Certificate And Cool Roaming Features