Security configuration

The SoftDevice allows the number of security manager protocol (SMP) instances available for all connections operating in central role to be specified by the application.

At least one SMP instance is needed in order to carry out SMP operations for central role connections, and an SMP instance can be shared amongst multiple central role connections. A larger number of SMP instances will allow multiple connections to have ongoing concurrent SMP operations, but this will result in increased RAM usage by the SoftDevice. The number of SMP instances is specified through sd_ble_cfg_set.