Over the years I kept upgrading my VDSL line and also my Wi-Fi network setup to benefit from increasing data rates offered by my fixed line carrier. With 802.11ac, I get around 350 Mbit/s in the downlink direction and 200 Mbit/s in the uplink direction with my Lenovo X250 notebook at my desk. When I move closer to the access point, I can get around 600 Mbit/s out of the link. But since I don’t work close to the access point, that’s more of a theoretical value for me. Now one could argue that this speed is more than enough for my Internet access. That’s true but since I also run a number of servers at home and occasionally transfer very large files or VM images, more is better and useful. So at some point it was time again to see if I could improve my Wi-Fi setup to get more than the 350 Mbit/s. 1 Gbit/s is the value to beat as that’s what I would get over Ethernet or fiber. Beyond that and I would have to upgrade my servers. As you can see in the title of this post, I could push my setup to a sustainable 800 Mbit/s at my desk.
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.
One 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:
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:
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:
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?
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.
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: