On Tue, Oct 02, 2012 at 05:23:28PM +0200, Peter Stuge wrote:
Hi Yann,
Start looking at the source code. Pick some entry point for a message that you understand. Follow the call graph through the source code, to learn about the data flow in OpenBSC. You will quickly find what the difference is between OpenBSC and a conventional BSC.
Hi,
on top of that the "BSC API"[1] is a good way to start to look at. There are currently two implementations. One for the NITB and one for the classic BSC. The NITB will handle the MSC/AuC/HLR/VLR functionality by direct function calls, the BSC will pack the data into GSM08.08 BSSMAP and send it to a MSC using SCCP-lite (SCCP on the IPA protocol). To use the "classic BSC" one needs a real MSC to connect to. My Smalltalk implementation is not very mature yet.
holger
[1] http://cgit.osmocom.org/cgit/openbsc/tree/openbsc/src/libbsc/bsc_api.c