Connection Time Out happening if remote device not responds for LL_LENGTH_REQ command

[sridharnaidu]

Hi,

I am using nrf52832 with soft device 3. I am operating on peripheral role, while i am initiating sd_ble_gattc_exchange_mtu_request  with desired MTU ,it internally sends LL_LENGTH_REQ command. The other side android application is not responding for this command and this case is observed in only in particular model phone. I observed after some time the connection is automatically terminated.BLE_HCI_STATUS_CODE_LMP_RESPONSE_TIMEOUT error code coming from phone. My understanding is soft device is closing the connection since the LL_LENGTH_REQ command is not answered from phone.

• Is there any way soft device can ignore this and do not initiate dis connection procedure?. 
• Is there any way we can stop LL_LENGTH_REQ command initiation from soft device?( since user don't have control on this in soft device 3)
• Is there any work around for this?

Thanks,

Sridhar.

[sridharnaidu]

Edited: S132 3.0.0 Soft device. BLE_HCI_STATUS_CODE_LMP_RESPONSE_TIMEOUT is coming from peripheral.

[Vidar Berg]

In s132 v3.1.0 you can disable the initiation of data length extension. I would recommend you to use this version. It is drop in compatible with s132 v.3.0.0

[sridharnaidu]

That means there is noway of doing it in s132 3.0.0 ?. Means externally stopping the data length extension initiation?

[Vidar Berg]

Correct, it is not possible to disable initiation of data length extension in v3.0.0. 

[sridharnaidu]

Is there any way soft device can ignore this? means when it didn't get  reply for LL_LENGTH_REQ command, soft device can ignore this and won't initiate disconnection procedure.

[Vidar Berg]

Unfortunately, the specification requires that the link is terminated after a procedure timeout, and it is it not possible to override this from the application.