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Created 2 December 1999 ... Updated 27 January 2006

About this site

This site is the personal website of Mischa Koning and even though it contains some information on my professional life and career, this information is my purely personal view on things. In case you think you may have any concerns regarding some of the content, please let me know and we can freely discuss and solve the issue. Contact details are on the main index page.


It all started with a little problem. When I decided to get my own domain name, I had looked at,,, and
but as you can see they were all taken. I couldn't think of any other cool domain name which made sense. was still available but in my opinion a domain name should be short, catchy and easy to remember.

Then one day I came across a numeric website, and the thought of having my own original Tymnet network sounded like a great idea. Of course I realise that most of you grew up without the Tymshare / Tymnet / Global Network Service or Concert Packet Services network and I'm not old enough to know the details from my memory either, so a little explanation of this network would be nice. For those who know it all you may skip this part and stay in the here and now.


tymnet Once upon a time there was no internet. Computers were big and work stations were connected to them by cables. Mid 1960's some engineers started a small company called Tymshare in Palo Alto/California. They bought a big server and some telephone lines and modems and sold processor time to people who wanted to use the machine. After some years multiplexer were used to reduce cost and the first hub-and-spoke computer network was born. Over the years the network grew bigger and bigger and with all the technological changes it was renamed in 1979 to Tymnet. Tymnet was growing rapidly and in 1984 bought by Mc Donnell Douglas, the aircraft construction company.

In the mean time a company called BT (British Telecom), was heading towards rougher times. Their home market was getting more competitive as competition started to move in after BT's privitisation in the early 1980's. BT decided that it would be a good idea to look across the borders of the United Kingdom to see if there was an international telecommunication need in multinational companies. They came across the Tymnet network and found out that Mc Donnell Douglas was moving back to its core business, i.e. building airplanes, and was willing to sell their network. BT Worldwide bought it in 1989 and renamed it into Global Network Services (GNS). All of McDD's Tymnet offices worldwide were taken over by BT and serious sales started.

1993 was a very special year for BT, not only because I joined the company but also because BT signed an agreement with the large American based telecommunications provider MCI. BT and MCI together started a new company and named it Concert. Concert became the backbone provider and the existing BT and MCI offices became the customer interface and took care of customer service and sales. GNS was renamed into Concert Packets Services (CPS) and handed over to MCI via a stock exchange. In the mean time Concert's Frame Relay network (CFRS) was launched. This was the time that many large CPS customers moved to the much faster CFRS platform and CPS started dying slowly. In the mean time MCI moved out of the Concert alliance and AT&T moved in. Tymnet is still owned and operated by MCI while Concert is building a new global Tymnet based network.

Sure but why 3106?

Now that you know all about tymnet and it's history, you're probably still puzzled about the reason for the 3106. Some more historic information is necessary.

When networks got larger and larger the need for interconnects between the different networks arose. Since X.25 was the most popular networking protocol in those days, the same standardisation organisation (CCITT, later renamed into ITU) decided to standardise the gateway protocol as well, this was filed under reference X.75. Since all networks use a different method of addressing they also decided to put a unique number in front of the proprietary addresses, this number became known as the DNIC, filed under reference X.121. This DNIC can be seen as the international country code with telephony. The Tymnet network was lucky enough to get X.121 number 3106 as this turned out to be a very nice number indeed as many years later a very nice homepage became known under this name, :o)

Let's call

It's time for a call:

LINE 00 LINK 00 FFFF 0015 1014 0BDA
3106 0203 0531 0601 3101 0100 00CC 0000 00

For most people these are just numbers, for X.25 people this is a call and for the lucky few who have still access to the Tymnet troubleshooting tools this is a call from Vienna/Austria to Rotterdam/Netherlands...

You sound like a nerd!

Well ok, on this page I do but hey, don't we all look back to our first real job with good feelings? Take a look at the rest of my website and you will find that the nerd level is pretty low. I just wanted to have a cool domain name and this seemed to be a good excuse... :o)

It was something from my past. At the moment I got my domain name I still worked regularly on Tymnet problems but it was not my main job anymore. It's really a network from the past but it still works fine for many customers. Since Tymnet engineers are a rare species these days, people still contact me to get their problems solved. In my first job, working for BT Netherlands, I got infected with the Telecommunications virus and liked the idea of being able to do everything remotely. Talking with machines in dark Africa was as easy as talking with machines in sunny California was as easy as talking with machines in rainy Amsterdam. Since then telecommunications has been my thing.

tymnet As said, Tymnet engineers are a rare species. Coincidence made for the fact that Concert's Tymnet group contacted me during the first week of my holidays after my job at DIS Vienna had finished. They were desparately looking for people with Tymnet knowledge and came across me. Since the job sounded nice and I was available it didn't take me a long time to decide to go back working with Tymnet, back to where it started...


The systems are obsolete now, Tymnet was switched off sometime during February 2004, only a few weeks ago. We've all been working hard (me until November 2002) to migrate the last customers off of Tymnet and we have succeeded, all customers have been migrated onto more current networks. An era has come to an end...

Now what we have is the internet, maybe I should apply for a new domainname, maybe for ?


To learn more about Tymnet, take a look at the following sites and pages

  • Paul Martijn - Dutch Tymnet supporter
  • Laroy Times - Tymnet historic overview from one of the founders
  • Imperial College London - Networking reference
  • "Reststop" Carl Baltrunas - A long time Tymnet supporter

  • BT
  • Concert
  • MCI / Worldcom