MTU negotiation event diffs between IOS and Android

[Linxi]

Dear Nordic:

My peripheral is configured to use MTU 247.

When connected by NrfConnect of IOS, I can receive NRF_BLE_GATT_EVT_ATT_MTU_UPDATED event and check the effecitve mtu.

But with NrfConnect Android, I receive NRF_BLE_GATT_EVT_DATA_LENGTH_UPDATED instead of NRF_BLE_GATT_EVT_ATT_MTU_UPDATED, and data length is 0x1B(27).

What makes the difference?  NRF52832/S332/SDK13, could you give me some advise?

[Simonr]

Hi

This is likely just a difference between the Android and IOS stacks. I suggest setting NRF_SDH_BLE_GAP_DATA_LENGTH to 251 in the sdk_config.h header file as well as the MTU update to maximize data throughput.

Best regards,

Simon