The sender discovers capable devices via a bluetooth-low-enery (BLE) beacon.


The sender connects to the mac-address (specified in beacon) via Rfcomm. If a user entered the wrong address, the connection will fail but the receiving device can still be found as the beacon is visible anyway.

In order to connect two devices via the cdp-protocol the connect messages have to be exchanged. During a successful connection the encryption is established.


After the connection is established the implementations exchange a list of possible alternative transports (e.g. WiFi or WiFiDirect) and try to upgrade to the faster transports (i.e. WiFi).