Editing Data link layer (section)

==Services==
The services provided by the data link layer are:
*Encapsulation of [[network layer]] data packets into [[Frame (telecommunications)|frames]]
*[[Frame synchronization]]
* In the [[logical link control]] (LLC) sublayer:
**[[Error control]] ([[automatic repeat request]], ARQ), in addition to ARQ provided by some [[transport-layer protocol]]s, to [[forward error correction]] (FEC) techniques provided on the [[physical layer]], and to error-detection and packet canceling provided at all layers, including the [[network layer]]. Data-link-layer error control (i.e. retransmission of erroneous packets) is provided in wireless networks and [[ITU-T V.42|V.42]] telephone network modems, but not in LAN protocols such as [[Ethernet]], since bit errors are so uncommon in short wires. In that case, only [[error detection]] and canceling of erroneous packets are provided.
**[[Flow control (data)|Flow control]], in addition to the one provided on the [[transport layer]]. Data-link-layer flow control is not used in LAN protocols such as Ethernet, but in modems and wireless networks.
* In the [[medium access control]] (MAC) sublayer:
**[[Multiple access method]]s for channel-access control, for example [[Carrier-sense multiple access with collision detection|CSMA/CD]] protocols for [[collision detection]] and re-transmission in [[Ethernet]] bus networks and hub networks, or the [[Carrier-sense multiple access with collision avoidance|CSMA/CA]] protocol for [[collision avoidance]] in wireless networks.
** Physical addressing ([[MAC address]]ing)
**[[LAN switching]] ([[packet switching]]), including [[MAC filtering]], [[Spanning Tree Protocol]] (STP), [[Shortest Path Bridging]] (SPB) and [[TRILL]] (TRansparent Interconnection of Lots of Links)
** Data packet queuing or [[Scheduling algorithm#In computer networks and multiplexing|scheduling]]
**[[Store-and-forward]] switching or [[cut-through switching]]
**[[Quality of service]] (QoS) control
**[[Virtual LAN]]s (VLAN)