In computer networking, the link layer is the lowest layer in the Internet Protocol Suite (commonly known as "TCP/IP"), the networking architecture of the Internet (RFC 1122, RFC 1123). It is the group of methods or protocols that only operate on a host's link. The link is the physical and logical network component used to interconnect hosts or nodes in the network and a link protocol is a suite of methods and standards that operate only between adjacent network nodes of a Local area network segment or a wide area network connection.
Despite the different semantics of layering in TCP/IP and OSI, the link layer is often described as a combination of the data link layer (layer 2) and the physical layer (layer 1) in the Open Systems Interconnection OSI model. However, TCP/IP's layers are descriptions of operating scopes (application, host-to-host, network, link) and not detailed prescriptions of operating procedures, data semantics, or networking technologies.
RFC 1122 exemplifies that local area network protocols such as Ethernet and IEEE 802, and framing protocols such as Point-to-Point Protocol (PPP) belong to the link layer.
| Internet protocol suite |
|---|
| Application layer |
|
| Transport layer |
|
| Internet layer |
|
| Link layer |
|
Read more about Link Layer: Definition in Standards and Text Books, Link Layer Protocols, Relation To OSI Model, RFC References
Famous quotes containing the words link and/or layer:
“John Brown and Giuseppe Garibaldi were contemporaries not solely in the matter of time; their endeavors as liberators link their names where other likeness is absent; and the peaks of their careers were reached almost simultaneously: the Harper’s Ferry Raid occurred in 1859, the raid on Sicily in the following year. Both events, however differing in character, were equally quixotic.”
—John Cournos (1881–1956)
“The writer in me can look as far as an African-American woman and stop. Often that writer looks through the African-American woman. Race is a layer of being, but not a culmination.”
—Thylias Moss, African American poet. As quoted in the Wall Street Journal (May 12, 1994)