On Mon, Oct 08, 2012 at 09:23:58PM +0200, Yann R. Moupinda wrote: > > > > > Hello everyone, > > thanks for the ideas you gave me about how i can learn more about the > communication between BSC and MSC in my sysmoBTS. Since last week i've been > looking at the source codes and it's still difficult for me to follow the > exchanged messages betwenn BSC and MSC. I don't have high programming skills.
well, it starts with the organisation of the sourcecode. E.g. src/libmsc contains the MSC functionality. E.g. take a look at osmo_msc.c it is glueing the "BSC API" to the MSC code. compl_layer3 (as of GSM 08.08) will be called for the first message on a newly opened RF connection. dtap will be called for every following message. > > Instead of using sysmoBTS as an autonomous self-contained GSM network (NITB > mode), i'd like to configure it in the BSC-only mode running the osmo-bts and > osmo-bsc. I read that i will need a MSC that can provide an A-over-IP > interface using SCCP-lite. I saw that the "on-waves/bsc-master" branch is > implementing such a SCCP and works have been done to create a GSM0808 like > API and move the MSC code inside OpenBSC over to use this API. So i was > wondering how far this project has been developed yet. Do you already have > any interesting results that can help me? If not, it can be also interesting > for me to know how you did your tests by implementing the bsc-only mode > (osmo-bsc)? Did you connect it to a real MSC or did you have anything else > emulating the MSC/HLR/VLR/EIR functions? on-waves/bsc-master is an old vendor branch, the same functionality is available in the master branch of openbsc. The src/osmo-bsc directory holds the BSC implementation. This adds GSM 08.08 parsing and message generation on top of the 'BSC API' (same interface as in osmo_msc.c but different implementation). The osmo-bsc has been used with various proprietary MSCs. There is no free MSC that will just do what you want at this point in time. I have the start of a MSC in Smalltalk but right now it is solving a non-standard usecase and is not a general MSC. Why do you need to see GSM 08.08 messages?
