We'll be seeing here Ethernet, and the great 802.x Family.
1. Introducing the Ethernet Family
Ethernet is a technology based on shared medium usage. Its foundation is CSMA/CD ( Carrier Sense Multiple Access with Collision Detection ).
There are actually 4 Ethernet types :
. Ethernet v1 : The original ethernet, now depracated
. Ethernet v2 : Evolution from Ethernet v1, In use
. IEEE 802.x + LLC
. IEEE 802.x + LLC + SNAP
Ethernet v1 was published in 1980. Ethernet v2 was published in 1982.
IEEE 802.3 was published in 1983.
IEEE 802.x is a formal standardization effort of Ethernet v1 and v2.
Nowadays, both Ethernet v2 and 802.x are used. In the case of cable-Lan, Home consummers products usually preffer to use the Ethernet v2 Frame, as it is less CPU intensive.
IEEE 802.x is never used alone, but with LLC ( 802.2 ) or LLC + SNAP ( 802.2 + SNAP )
Why am I using 802.x instead of, say, 802.3 : Because the Ethernet family is vast, and encompasses different technologies. Here are some examples :
802.3 = Cable ( Ethernet cable )
802.11 = Wifi
802.15.1 = Bluetooth
Let's sum-up all this in a chart :
Let's complete this chart with some known protocols :