https://devzone.nordicsemi.com/f/nordic-q-a/2800/pipe-always-not-available-for-a-notification-enabled-characteristicHi, I&#39;m new to nRF8001 SDK and Bluetooth and I hope my questions are not too stupid lol. So here it goes: I&#39;m using the Nordic nRF8001 SDK to implement a self-defined service with vendor specific UUID, in order to communicate with an iPhone appen-USTelligent Community 13Wed, 18 Jun 2014 16:38:29 GMThttps://devzone.nordicsemi.com/thread/10753?ContentTypeID=1Wed, 18 Jun 2014 16:38:29 GMT137ad170-7792-4731-bb38-c0d22fbe4515:db608f41-530a-4404-b8a4-571e45e46709Richard T<p>Thank you for the quick response!</p><div style="clear:both;"></div>https://devzone.nordicsemi.com/thread/10752?ContentTypeID=1Mon, 16 Jun 2014 11:48:37 GMT137ad170-7792-4731-bb38-c0d22fbe4515:b5b9cae1-eabe-463f-b9bf-8871af9a5f2erun_ar<ol> <li>Yes, the central can enable/disable notifications or indications by writing to the CCCD.</li> <li>There is always Link layer acknowledgment in BLE, so this shouldn&#39;t be a problem. Note that iOS doesn&#39;t necessarily remember the states of the CCCD&#39;s of a device after disconnecting and reconnecting to a device.</li> <li>You can check if the pipe is available using lib_aci_is_pipe_available. Note that we had a bug in the earlier SDK where the pipe updating was wrong. Make sure youe use the latest SDK.</li> <li>Yes. notice the earlier mentioned caveats.</li> </ol><div style="clear:both;"></div>