Do we have feature/functionality in OSMO-BSC similar to authorized-regex of OSMO-NITB where a IMSI prefix or regex is used to determine if the subscriber is permitted to register to the network or not. I've tried to looked at the osmo-bsc manual but I haven't seen any configurations related to the said feature/functionality. I've tried also the access-list configuration but I think it's no longer supported in latest version.