Layer
3 refers to the Network layer of the commonly-referenced
multilayered communication model, Open Systems Interconnection
(OSI). The Network layer is concerned with knowing the address
of the neighboring nodes in the network, selecting routes
and quality of service, and recognizing and forwarding to
the Transport layer incoming messages for local host domains.
A router is a layer 3 device, although some newer switches
also perform layer 3 functions. The Internet Protocol (IP)
address is a layer 3 address.
|