Computers and routers that are interconnected in a wired or wireless network (Local Area Network (LAN)) via Ethernet compete to transmit data packets. In such a network, the Ethernet is the shared medium. A shared medium is also called a broadcast channel, multi-access channel, or random access channel. The problem is how to determine which device is next to use the shared medium as they all compete for access. The MAC protocol is designed to resolve the problem by providing a unique identification number (MAC address) for network adapters and access control for computers and routers on the network.