Voice over NR Whitepapers

Now that the non-Standalone (NSA) flavor of 5G has been pretty much established around the globe, it is likely that more focus is put on the 5G standalone (SA) flavor of the technology. In effect that means two things: Instead of using LTE as an anchor for a 5G air interface connection, 5G can stand on it’s own feet. This requires a 5G core network (5GC) with a radically new service based architecture. One existing application that needs to be supported over 5G SA and the 5G core network is of course voice. This means that Voice over LTE (VoLTE) needs to evolve to Voice over NR (VoNR). Rohde & Schwarz has recently published great whitepaper on the topic which I liked very much, so I thought I’d say a few words about the topic here.

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Remote Support with a Self-Hosted Remotely Instance

I’m always on the lookout for solutions to improve my remote working and support capabilities and recently came across ‘Remotely‘, an open source and self-hostable remote support solution for Windows and Linux. Self-hosted and open source, hm, sounds interesting, I thought, just what I like for privacy and confidentiality reasons. So I had a closer look!

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Stress Testing Guacamole

In the previous post, I had a look at Guacamole, an open source client-less remote desktop gateway. It’s a cool piece of software and I have already used it with 12 people connecting to the same number of workstations in the cloud. In this setup, the central Guacamole server that I equipped with 8 vCPUs hardly required any CPU resources at all. However, most of the time, not much was changing on the remote desktops, so my scenario was not very demanding. So while that’s good to know, I wanted to know the limits of my 8 vCPU setup, so I stress tested my setup. A fun experience!

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Command Line Heroes – Season 7

Wow, it’s only a year ago since I was three years late to the ‘Command Line Heroes‘ podcast. In case you haven’t seen my post then, ‘Command Line Heroes’ is a podcast about, well, the title says it all. Ever since it’s first season, the show’s host Saron Yitbarek has looked at people and coding related topics, and it’s hard not to listen to a new episode the second it pops-up in my podcasting app. Season 7 has just started, so I thought I’d mention it here, and it is all about how the Internet became what it is today. Highly recommended, as it’s a wonderful mix of history and thoughts how the past has shaped what we are working with today.

Kernel Trouble on my T430 – How to Go Way Back To Fix It

Over the years, I had only little trouble during Ubuntu Linux system updates. Very occasionally, Virtualbox requires a bit of care but that was pretty much it so far. The more surprised I was when I recently saw this on the screen of two of my older notebooks after running a security fix update on Ubuntu 20.04:

So what’s going on!?

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Online Workshops with Virtual Desktops in the Browser

Earlier this year, I started experimenting with how to make online talks and learning sessions online more interactive. Yes, after a year of conferences being online-only, I grew a bit tired of staring into a tiny camera lens and only getting little feedback. So I came up with cloud based virtual desktops for interactive online hands-on workshops, and I’ve held quite a number of them since then on topics such as Docker, Kubernetes and mobile network tracing. In addition to describing the setup in my blog post over here, I’ve recently given a talk about how to set up such a system. You can find the original talk in German here and with an English simultaneous translation here. And as I was hoping, I got interesting feedback after the talk on how to further improve the setup.

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Tip of the Day: Line Numbers in Nano

For modifying config files and inspecting logs on remote servers, my tool of choice is the shell based nano editor. It’s a wonderful tool that is simple to use. But there is one feature that has seemingly been missing for many years: An easy way to activate line numbers on the left side of the text window. Recently, I have found out, only by accident, that there’s a shortcut to switch them on and off:

ESC + #

Strangely enough, the shortcut is not mentioned in the documentation and I can’t find any hints on the Internet either. Quite puzzling. Anyway, it works great and its so useful that I thought I needed to share this 🙂 !

SSH Tunnels, TCP Port 443 and Socat

In my private cloud setup, I use SSH tunnels a lot to create a redundant path from the Internet to services I host at home for times when my DSL line is down. It doesn’t happen a lot, but it does happen. The method is also ideal for hosting services at home in case the ISP does not assign a public IP address to the link. Have a look here and here for the details. When I recently wanted to add two new tunnels for port 80 and 443, which I did not forward so far, I was a bit baffled that this didn’t work out of the box.

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Keeping Track of Document Research Data

Today, I have an announcement about a quality time software project of mine:

Many years ago, I started helping a member of the family to better organize the qualitative research data that accumulated during a digital humanities research project. At first, using an Excel file to categorize document references, notes on books, etc., worked quite well. However, over time, the Excel file grew to thousands of cells and 2 MB of pure text data. Some cells suddenly contained several pages of text, and the research project became a multi-person endeavor in which several people needed to work on the data at the same time and from different places. This pretty quickly resulted in unsettling questions such as ‘which of those many Excel files contains the latest version of the data’. And, as in any research project that grows, finding and modifying data in the sheet became more and more difficult as well.

At this point, the situation became too chaotic for my taste so I decided to program a web-based Document Research Database project in my quality time to help out. As others in our circle of researcher friends have found the solution quite helpful for their work as well, I have now open-sourced the project to make it available to a wider audience. The source code is GPL-3 licensed, so anyone can now use it for free by setting up their own instances.

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Automating my Cloud Updates with Ansible

I’ve thoroughly dockerized the services I run in my cloud at home and in a data center over the past months. However, at last count, there are still over 25 servers and virtual machines running on which I run various services. I don’t have a problem with that, but keeping them all updated and rebooted is not a very exciting task. So perhaps Ansible is the tool for automating my cloud updates?

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