Author: Martin

In the previous blog entry, I’ve been looking at a number of different commercial video conferencing solutions and if they offer native Linux support. There are a couple of fabulous products with good Linux support out there that easily support sessions with 15-20 simultaneous video participants. Unfortunately, from a privacy and confidentiality point of view, most of them don’t fare very well at all.

As confidentiality and privacy are very important to me, a potential solution for me and others is Jitsi, which is open source from client to server and can be installed on private infrastructure. The big question for me was however: How many video participants can the clients and the server handle in a single conference? A search on the web didn’t really result in a good answer. So I set out to find out for myself.

Continue reading Jitsi Meet and the Number of Video Participants

Like many others in the industry, I am doing a lot of work in my ‘home office’ lately while the Corona virus continues to make normal life as we know it impossible. A lot of people, including myself, have started to use various video calling and conferencing solutions a lot more than before and I was quite surprised how many of those closed source and commercial solutions have a native Linux implementation.

Continue reading Linux and Conferencing Solutions

Fun post today: Once upon a time, the term ‘flat rate‘ for Internet connectivity meant that you pay a monthly fee and could use the Internet as much as you wanted. But then a lot of mobile network operators started to misuse the term. While still offering a fixed monthly price, the amount of data was limited. Once that amount was used up a speed step-down to a few kilobits per second would be enforced for the rest of the month. At these speeds, Internet connectivity is pretty much useless these days. So much for the ‘flat rate’, the term was totally burned.

Now, more and more operators have started to offer ‘real’ flat rates without a speed step-down. But how do you advertise this? One German network operator has decided to use the German word “endlos” (endless). I admit I had to smile. After years and years of using English words in advertisements because it’s hip and cool, they had to revert back to German as they’ve run out of English words and ideas that haven’t been misused in this context.

5G is slowly making its way into Cologne with incredible date rates. Recently, however, I discovered just what it means to have a simple insulating window between you and the network outside.

Continue reading 600 Mbit/s Outside – 6 Mbit/s Inside

When you look through the 5G core network specification documents of 3GPP such as TS 23.501 and 23.502 the idea I got was that it’s pretty much the same as before. Yes, the interfaces and network components have new names but by and large the 5G core network does the same things as today’s core networks and also pretty much in the same way. One thing that stands out just a little bit, though, is that control plane network components are now referred to as ‘functions’ and that the interfaces between them are now ‘service based’. In practice, that means the interactions are now stateless and use http query/responses and data is encoded in JSON format instead of the stateful connections with protocols for signaling interactions as before. O.k. so fine, I thought, 3GPP has moved to web based technologies. But that’s only the tip of the iceberg according to this interesting paper from 5G Americas on ‘5G and the Cloud’.

Continue reading The Cloud Native 5G Core Network

A couple of weeks ago in January 2020 I spotted the first 5G antenna at the cell site that serves my home in Cologne on my way home. My first reaction: ‘Hm, that wasn’t there this morning…’. It wasn’t switched-on straight away. but when I came back from vacation early in February, I was greeted with a 5G logo after arriving at home. And even without ‘holding the phone the right way’ I immediately got well over 660 Mbit/s out of the downlink channel.

Continue reading I’ve Got 5G At Home Now!

Recently I’ve been looking a bit at the 5G NR Radio Resource Control (RRC) protocol in 3GPP TS 38.311 to get an idea how it is structured and how it compares to the LTE RRC protocol specified in 3GPP TS 36.331. As Ralf points out in the comments below (thanks very much!) some parts of it are already used today to embed 5G configuration information in 4G RRC messages for EN-DC, while other parts will become relevant with 5G NR Standalone, i.e. once a 5G core network is available and devices and the gNBs have implemented standalone operation.

Continue reading 5G RRC Protocol And How It Compares to 4G RRC

Already back in 2018 I wrote a post that one new thing about 5G in TDD band n78 will be that network operators need to agree on a common uplink/downlink pattern and in addition synchronize their networks. Recently I was asked to what level of accuracy the networks need to be synchronized so I did a bit of research to find out.

Continue reading 5G TDD Inter-Operator Network Synchronization

A couple of weeks ago, Heise had a post on the newly published EU roaming report. Via this page you can get to the actual document that indeed has many interesting insights into pricing, cost and use of roaming in the EU before and after roaming charges became a thing of the past in June 2017. The document has 98 pages full of insights and here are the points that I found particularly interesting.

Continue reading Interesting Insights from the EU’s Roaming Report

While I was investigating potential congestion issues in the roaming backhaul link of mobile networks I noticed again once more that this is by far not the only place where network operators are not providing enough capacity during busy hours in the evening. Another unfortunate example are fixed line access networks. Here are two examples over which I trip frequently.

Continue reading Congested Peering and Transit