Possible fault in Experimental: GATT Module documentation?

[Mathias]

Hi,

Just a small question. In the SDK 15 documentation for the Experimental: GATT Module documentation, could it be that the following sentence "The default value that the module uses is NRF_SDH_BLE_GATT_MAX_MTU_SIZE, which is set to 251 bytes.", should be 247 bytes instead of 251? As I understand,  the Data Length has 4 bytes overhead, so if maximum data length is 251 bytes, then maximum MTU should be 247 bytes (to fit in one packet)? Same as if data length is 27 bytes, then MTU is 23 bytes max. (to fit in one packet)?

Kind regards,

Mathias

[Kenneth]

Should be 247 yes, I believe the example does so (from sdk_config):
#define NRF_SDH_BLE_GATT_MAX_MTU_SIZE 247 

For anyone interested you may find this external page useful:
https://punchthrough.com/blog/posts/maximizing-ble-throughput-part-2-use-larger-att-mtu