Editing Internet protocol suite (section)

==Link layer==
{{main article|Link layer}}
The protocols of the link layer operate within the scope of the local network connection to which a host is attached. This regime is called the ''link'' in TCP/IP parlance and is the lowest component layer of the suite. The link includes all hosts accessible without traversing a router. The size of the link is therefore determined by the networking hardware design. In principle, TCP/IP is designed to be hardware independent and may be implemented on top of virtually any link-layer technology. This includes not only hardware implementations but also virtual link layers such as [[virtual private network]]s and [[tunneling protocol|networking tunnels]].

The link layer is used to move packets between the internet layer interfaces of two different hosts on the same link. The processes of transmitting and receiving packets on the link can be controlled in the [[device driver]] for the [[network card]], as well as in [[firmware]] or by specialized [[chipsets]]. These perform functions, such as framing, to prepare the internet layer packets for transmission, and finally transmit the frames to the [[physical layer]] and over a [[transmission medium]]. The TCP/IP model includes specifications for translating the network addressing methods used in the Internet Protocol to link-layer addresses, such as [[media access control]] (MAC) addresses. All other aspects below that level, however, are implicitly assumed to exist and are not explicitly defined in the TCP/IP model.

The link layer in the TCP/IP model has corresponding functions in Layer 2 of the OSI model.