gb_proxy keeps stale PTP-BVCI <-> NSVCI mappings
When BVCI A first establishes a connection through NSVCI/NSEI B, then later establishes a connection through NSVCI/NSEI A, gb_proxy permanently keeps a stale proxy mapping associating BVCI A with NSVCI B.
This causes all downlink messages from the SGSN to be routed still through NSVCI B, despite now NSVCI A being the correct one.
Yeah, the BVCI <-> NSVCI mapping doesn't even make sense now that one NSE could have multiple NSVCs.
Not sure if we have a similar issue in the new gbproxy or if it is already taken care of. Some code related to this got #if 0'd in rx_bvc_reset_from_bss() (gbproxy.c line 793).