The LLC sublayer

The LLC sublayer typically moves the data between the software applications on a system onto the physical hardware components of a network, such as the Network Interface Card (NIC) or the media cables. When bits are received by the LLC, it helps with the reassembly process and passes them up to the upper layers of the protocol suite, such as the TCP/IP stack.

At this point, you may be wondering where exactly the LLC is located on a computer, switch, or even a router. The answer is quite simple—it is implemented in software within the firmware or the operating system of the local device. LLC is often described and referred to as the component driver software which interconnects the device's NIC to the operating system. 

The NIC's driver software is what interconnects the physical hardware onto the operating system for communication on the network. The following diagram shows both the sub-layers of the Data Link Layer: