The question of parameters in PEER_MANAGER

[CFF.K]

hi, 

I try to realize all parameter functions in the peer manager. ( I use SDK 15.2.0 )

I expect to design is bond total max 4 in the product. I have some question in below:

Q1: How do I count or limit the amount of bond? (Like NRF_SDH_BLE_PERIPHERAL_LINK_COUNT or NRF_SDH_BLE_CENTRAL_LINK_COUNT)

Q2: What does the PM_FLASH_BUFFERS use for? I think this amount follows the total bond amount, but my mind is wrong after I tested it.  because the nRF52 still bond for 4 mobiles and transmit data when I set PM_FLASH_BUFFERS=1.

Q3: What does the PM_RA_PROTECTION_ENABLED use for? Could you give an example, let me know the situation.

[Amanda Hsieh]

Hi Ken,

Q1: How do I count or limit the amount of bond? (Like NRF_SDH_BLE_PERIPHERAL_LINK_COUNT or NRF_SDH_BLE_CENTRAL_LINK_COUNT)

You can use ble_conn_state_central_conn_count and ble_conn_state_peripheral_conn_count which are the functions for querying the total number of connections in which the role of the local device is. Please refer to  nRF5_SDK\examples\ble_central\ble_app_multilink_central and examples\ble_peripheral\experimental\ble_app_multiperipheral to limit the count.

Q2: What does the PM_FLASH_BUFFERS use for? I think this amount follows the total bond amount, but my mind is wrong after I tested it.  because the nRF52 still bond for 4 mobiles and transmit data when I set PM_FLASH_BUFFERS=1.

 PM_FLASH_BUFFERS is used for the number of internal buffers for flash operations. If your application is doing a large write you could try increasing PM_FLASH_BUFFERS (in sdk_config.h). 

Q3: What does the PM_RA_PROTECTION_ENABLED use for? Could you give an example, let me know the situation.

PM_RA_PROTECTION_ENABLED is configured to reject repeated security requests. See Architecture documentation:

Repeated pairing attempts protection (optional)
You can enable protection against repeated pairing attempts by setting "PM_RA_PROTECTION_ENABLED" in the sdk_config.h file. In this mode, the Peer Manager uses the timing module to keep track of peer devices that failed at the pairing procedure. Future pairing attempts from these peer devices are rejected for a certain period of time. More detailed description of peer tracking policy can be found in Bluetooth Core Specification v5.0, Vol 3, Part H, Section 2.3.6.

-Amanda H.