Hi all,

During experimenting with RACH requests in my virtual Um-interface
environment, I found an interesting issue in OpenBSC. According to
the specifications, every RACH request should contain BSIC value of
target base station, and if I understand correctly BSC (or BTS?)
should ignore such requests, where rach_bsic != bts_bsic (Ghost RACH).

Meanwhile, when I send all-zero sequence (just for testing) on RACH
lchan, BSC allocates me a channel despite bts_bsic != 0x00. It probably
also explains the reason, why sometimes in a real OpenBSC + OsmoBTS
setup I see channel requests, followed by channel allocation without
any further response from MS side.

So, do we have any BSIC matching functionality implemented somewhere?
If not, I could try to open an issue and implement it.