Editing Medium access control (section)

== Functions performed in the MAC sublayer ==

According to IEEE Std 802-2001 section 6.2.3 "MAC sublayer", the primary functions performed by the MAC layer are:<ref>{{cite web |url=http://standards.ieee.org/getieee802/download/802-2001.pdf |archive-url=https://web.archive.org/web/20030429223052/http://standards.ieee.org/getieee802/download/802-2001.pdf |url-status=dead |archive-date=April 29, 2003 |title=IEEE 802-2001 (R2007) IEEE Standard for Local and Metropolitan Area Networks: Overview and Architecture |publisher=IEEE}}</ref>

* Frame delimiting and recognition
* Addressing of destination stations (both as individual stations and as groups of stations)
* Conveyance of source-station addressing information
* Transparent data transfer of LLC PDUs, or of equivalent information in the Ethernet sublayer
* Protection against errors, generally by means of generating and checking frame check sequences
* Control of access to the physical transmission medium

In the case of [[Ethernet]], the functions required of a MAC are:<ref>{{citation |title=IEEE 802.3-2002 |url=https://standards.ieee.org/ieee/802.3/3259/ |archive-url=https://web.archive.org/web/20190616081014/https://standards.ieee.org/standard/802_3-2002.html |url-status=live |archive-date=June 16, 2019 |section=4.1.4 |publisher=IEEE}}</ref>

* receive/transmit normal frames
* half-duplex retransmission and backoff functions
* append/check FCS ([[frame check sequence]])
* interframe gap enforcement
* discard malformed frames
* prepend(tx)/remove(rx) preamble, SFD ([[start frame delimiter]]), and padding
* half-duplex compatibility: append(tx)/remove(rx) MAC address