Anyone who considers protocol unimportant has never dealt with a cat.
—Robert A. Heinlein
The Logical Link Control and Adaptation Protocol (L2CAP) is a protocol multiplexing layer that enables Bluetooth low energy to multiplex three different channels. It also enables segmentation and reassembly of packets that are larger than the underlying radio can deliver. On a Bluetooth classic radio, the L2CAP layer also performs many additional, complicated operations.
One of the basic concepts for Bluetooth low energy is a radically different connectionless model; this means that you only have to create a connection when you need to send data, and the device can always disconnect ...