One thing that has been bugging me for a while is how to better automate PDF generation from camera images that first need to be ‘exif orientation info cleaned‘, rotated, and shrunken. There are great tools and command line options available for each individual task but nothing really useful for GUI users to combine them into a single action. So I set out to build a GUI tool for Linux myself for the purpose.
Continue reading Nautilus Extension for Fixing and PDF-ing ImagesOne command line tool that has come in quite handy many times over the years when dealing with Wi-Fi networks is ‘iw’. With this command you can scan the Wi-Fi bands for networks and get the configuration and capabilities of each in a detailed list. It’s perfect to find out, for example, which options are supported by an Access Point. Here’s an example of my 802.11ac capable access point:
Continue reading How To Get The Capabilities of an 802.11ac Access Point
Most cellular network operators around the world still have a circuit switched core network today for voice and SMS services for their 2G/3G access networks. There are a few exceptions like one operator in India that launched with an LTE-only VoLTE network a few years ago. But apart from a few, that is the status quo. And it’s unlikely to change for most operators for the following reasons:
Continue reading Verizon: The End Of Circuit Switching – The End Of An Era
Out of the box, BigBlueButton and Greenlight do not have an easy way to link to an imprint or privacy statement. As I am operating a server for others, that’s a bit of a problem as I really want to inform people how the server and the service deals with private data. So when I had a bit of time, I had a closer look how an imprint and privacy statement link could be added to the footer (Powered by Greenlight…) on every page. In the end it boils down to modifying the Greenlight source which requires a bit of effort the first time around. However, once you know where to look and what to do, it can be done in a few minutes. So here’s my procedure:
Continue reading BBB – How to Add an Imprint and Privacy Statement
After having had a look at the data rate of Conversations voice and video calls, the next thing I wanted to know was which underlying technology is used for the audio and video streams. Building such a thing from scratch, including authentication, encryption and overcoming NAT firewalls is a monumental task. So how was it done?
Continue reading Conversations: The Technology Behind Voice and Video Calls
For the past two months I and other members of the household have mostly worked from home. That obviously had an impact on the amount of data received and sent over the Internet. But how much and what has actually changed? To better answer that question, I had a look at my router statistics.
So there we go, the Conversations XMPP messaging app has voice and video calls now. A dream come true! Pretty much everyone I used it with so far was stunned by the audio and video quality of the calls. So I was highly interested, of course, to have a closer look at the data rates during audio and video calls.
Continue reading Conversations – The Data Rate of Voice and Video Calls
An interesting piece of data when operating a video conferencing server is how much data is transferred over the course of a week or a month. When I initially calculated the potential amount of data my BigBlueButton server could potentially consume over the course of a month with 70 people in 4 sessions all showing their videos, 10 hours a day, 5 days a week, I came up with around 25 TB per month. That would have been all right since my virtual server rental contains 20 TB of traffic a month, and each additional TB is billed at a euro or two. But that was the theory, how about practice?
In 2019 and 2020, I’ve seen first Wi-Fi 6 (802.11ax) capable devices coming to the market, mostly smartphones. On notebooks, the standard still hasn’t made a real impact, even the current Lenovo Thinkpad X390 still comes with a Wi-Fi 5 (802.11ac) modem. Also, on the Access Point side, first products have become available but the impact so far is still small. Nevertheless, now is the time to have a look at the spec and here are a number of resources that give a good technical overview of what’s new:
O.k., you must have figured it out by now, I’m a huge BigBlueButton fan. So while that is certainly true, there are a number of things I have noticed over the past few weeks that are not so nice (yet) and actually get in the way of getting some things done in an efficient way.