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What we do

Again we will provide external telephony connection to the congress by linking the DECT base station of Eventphone (POC) to Versatel via ISDN over IP tunnel. You will be able to dial to the national fixed and mobile telephone network for free, except value added numbers and emergency numbers. Just use your DECT phone as you would do it at home.

Also we will connect the GSM test network (using OpenBSC) with the DECT and public network. (The GSM network will be setup by Harald Welte and other project members. It will be officially licensed by the German regulation authority BNetzA.)

The connections are both realized with Linux-Call-Router, a software based PBX, specially designed for ISDN/GSM and low latency. In conjunction with mISDN driver, it connects to E1 links (S2M), S0 links, virtual IP links, as well as to Asterisk PBX using chan_lcr channel driver for SIP and other protocols.

Use your DECT Telephone

The outdial has changed last year, so read this: To dial to a German number, just dial the area code and number as you would do elsewhere in Germany. For Berlin you also need to dial the area code! Example: 030 1234567 (dialing to Berlin) For our foreign visitors: In Germany the area code always starts with the '0', so if you like to dial an German number like +49-xxx-yyyy, then you remove the country code (49) and add the '0' for accessing the area: 0-xxx-yyyy.

To dial inside the congress, you need to dial the four digits code of the phone you like to reach. (Don't add 0 or any other prefix in front of it.)

To dial to the congress from German telephone network, dial 0461-5056623-xxxx, where xxxx is your phone number at the congress. To dial from outside Germany, dial your international access code and then +49-461-5056623-xxxx.

Use your GSM Telephone

To register an extension number for you GSM mobile, visit the Eventphone Guru. One you have registered, trigger you manual network search on you mobile phone. Select the network "262 42". Now you need to dial your received token (from the Eventphone Guru). The network will then assign your extension number to your mobile subscriber identity (IMSI).

Special Projects this year

Interoperability test with OpenBSC

An interface allows Linux-Call-Router to use OpenBSC and a Base Stations to build a GSM network with access to ISDN/DECT phones and the public fixed network. We like to test and improve stability of both GSM and Linux-Call-Router, as we did last year.


The major work of last year was implementing a GSM protocol stack of the mobile phone. Together with some phone's hardware, it is possible to log into a GSM network and make / receive calls together with a valid SIM card. We will show this in practice. This stack is opensource and available at OsmocomBB website.

GSM Helpdesk

Last year we had the first GSM network on this congress. This year the Osmocom project will provide own SIM cards for the test network. We will help to use them and regular SIM cards, and answer questions.

Visit us

Further more we will show the Linux-Call-Router software and how to connect it to Asterisk. Other toppics are ISDN tunneling, real-time audio processing, VoIP.

Required Seats & Space

We would like to sit close to the POC for better communication and easier linking the DECT PBX with our PBX. Additionally we will do GSM helpdesk.

We are four people but other friends and visitors (helpdesk) join us from time to time, so we would like to have 6 seats, as we had last year.

Contact us

  • jolly AT eversberg DOT eu
  • before and after congrees: +49-4644-973171
  • during the congress dial 9000 or from outside: +49-461-5056623-9000


Archived page - Impressum/Datenschutz