Editing OSI model (section)

===Layer 2: Data link layer===
{{main|Data link layer}}
The data link layer provides [[node-to-node data transfer]]—a link between two directly connected nodes. It detects and possibly corrects errors that may occur in the physical layer. It defines the protocol to establish and terminate a connection between two physically connected devices. It also defines the protocol for [[flow control (data)|flow control]] between them.

[[IEEE 802]] divides the data link layer into two sublayers:<ref>{{cite book|title=IEEE Std 802-2014, ''IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture''|publisher=ieee|section=5.2 RM description for end stations|doi=10.1109/IEEESTD.2014.6847097|isbn=978-0-7381-9219-2}}</ref>
* [[Medium access control]] (MAC) layer – responsible for controlling how devices in a network gain access to a medium and permission to transmit data.
* [[Logical link control]] (LLC) layer – responsible for identifying and encapsulating network layer protocols, and controls error checking and frame synchronization.

The MAC and LLC layers of IEEE 802 networks such as [[802.3]] [[Ethernet]], [[802.11]] [[Wi-Fi]], and [[802.15.4]] [[Zigbee]] operate at the data link layer.

The [[Point-to-Point Protocol]] (PPP) is a data link layer protocol that can operate over several different physical layers, such as [[synchronous serial communication|synchronous]] and [[asynchronous serial communication|asynchronous]] serial lines.

The [[ITU-T]] [[G.hn]] standard, which provides high-speed local area networking over existing wires (power lines, phone lines and coaxial cables), includes a complete data link layer that provides both [[error correction]] and flow control by means of a [[selective repeat|selective-repeat]] [[sliding window protocol|sliding-window protocol]].

Security, specifically (authenticated) encryption, at this layer can be applied with [[MACsec]].