BSC doesn't release RF conenction or SCCP connection after main signalling link is closed
If a MS sends us an "RLL RELEASE IND" on SAPI0/DCCH, it closes the main signaling link.
TC_chan_rel_rll_rel_ind in the ttcn-3 BSC_Tests.ttcn to produce this scenario.
- attempt to re-establish it
- properly close the Radio channel (RF CHAN REL, ...)
- close the SCCP/A connection
I'm not entirely sure what's the specified action at that point. The best is probably to drop the RF channel and A connection in such situations, rather than trying to recover from something that clearly looks like an implementation bug of a phone.