The WebShop for the SIMtrace hardware can be found here. We are using a CA-Cert signed SSL certificate and your browser vendor might not like it. Setting up, or mostly modifying the webshop was my first encounter with rails. In some ways it is a great framework, in others with a Smalltalk background there are some tears in my eyes. This is using spreecommerce because I wanted something that is not done in PHP and is not following the OpenCore…
I ended up needing to configure FreeSWITCH to use a Sangoma ISDN card. At first we were foolish and used the setup script to install libraries into our system. Cleaning up It took dpkg -S and manual filtering to clean this mess. On a debian system there are files in /usr/ that do not belong to packages, these can be links to /etc/alternatives, or in case of python be bytecode files (*.pyc). Second attempt with building packages The next attempt…
One of the benefits of having a dynamic language like Smalltalk is that it becomes easier to experiment. For one of my current projects I am dealing with some simple USSD message handling and want to see how much load my application and the backend system can handle. Using the Smalltalk TestPhone this becomes quite easy. The first thing I do is to make up an Identity. This includes the IMSI and the AuKey (e.g. COMPv1 as found in libosmocore)…
The Professional Mobile Communication Research Group of Beijing Institute of Technology (BIT) was kind enough to send us their TETRA Wireshark dissector. They went through the specification and created ASN1 files out of the tables, I helped with the integration and cleaning to get the code into wireshark and the wireshark developers were kind enough to do a fast review and the code is now merged. The next part is to extend the GSMTAP dissector to pass on the tetra…
One year ago I was starting the on the BSC NAT application from a Hotel room in Munich, I was flying from Taiwan to Munich and was happy to see the snow from my window. Shortly after this I began to implement something we called cellmgr_ng. The job was to take MTPLevel3 coming out of a library and put the SCCP payload into the IPA protocol and send it to a MSC. As part of MTP Level3 I had to…
At the 27C3 we were running a GSM network and during the preparation I noticed a strange performance problem coming from the database library we are using running. I filled our database with some dummy data and created a file with the queries we normally run and executed time cat queries | sqlite3 file as a mini benchmark. I also hacked this code into our main routine and ran it with time as well. For some reason the code running…
I started to play with smalltalk somewhere in February, more specific with the GNU Smalltalk implementation. Like it is with any new language and class library it takes a while to get productive and it took me until somewhere the last month where I finally started to do GSM handling in Smalltalk and thanks to laf0rge the code is now in a public repository and hosted along the other Osmocom projects. You can see all the subprojects over here. So…
A small service announcement. The bsc_msc_ip from on-waves/bsc-master is now dead and one can use osmo-bsc from master. It has the same functionality but is implemented in a cleaner way making it more easily extandable. The biggest benefit of a open/free BSC equipment is the flexibility. If your network is a bit different to what people have thought out 30 years ago, you are now in the position to easily change that. E.g. your BSC could have different MSC connections…
Is there someone that can provide me with a trace with Cell Broadcast Services on the Abis link? I am not really figuring out what should be provided to the BTS… I assume that the nanoBTS takes care of scheduling the message and one provides one big message instead of the four separate things? Please comment, drop me an email or such.
I am almost back from a trip to iceland, I was fortunate enough to focus exclusively on GSM. In the last week I have continued to build osmo-bsc (a true BSC based on code from the on-waves/bsc-master) branch, I have worked on the NAT to make the IMSI filtering more useful and to add (hardware) transcoding to the MGCP MGW. The NAT changes are already in production, the transcoding will follow soon. IMSI filtering in the NAT/MUX. There is the…