Ethernet

Ethernet is a method for communication also called CSMA/CD (carrier sense, media access / collision detect). It was developed at DEC first. It was cheaper than token ring for a Local Area Network (LAN) so it became the industrial standard. Ethernet has historically been used on copper cabling up to Gigabit speeds, but fibre-optic cabling is becoming very popular especially at Gigabit speeds. When ethernet is in a half-duplex setting (possibly connected to a hub) collisions can occur when two or more NICS broadcast at the same time. When a collission is detected a NIC will back off a random amount of time and try again, because the other cards also back off a random amount of time the odds are low that they will collide again.

Ethernet

Has a bandwidth of 10 Mbps (Mega bit per second). It can work in full duplex and half duplex mode. The maximum length of one copper ethernet cable between 2 NIC's is 100 meters, 200 meters if a ethernet repeater is used, which boosts the signal.

Fast Ethernet

Has a bandwidth of 100 Mbps. It can work in full duplex and half duplex mode. The maximum length between 2 NICS is the same as 10 Mbps ethernet.

Gigabit Ethernet

Has a bandwidth of 1000 Mbps. It can work in full duplex and half duplex mode.

10 Gigabit Ethernet

Has a bandwidth of 10 Gbps (Giga bit per second). It probably works in full duplex mode.

Copper Cabling

Ethernet copper cabling also called Twisted Pair cabling is composed of 4 pairs of copper wire which are twisted between the pairs and also twisted around in their plastic protective coating. The twist is to ensure shielding which is questionable. The ends of ethernet cabling are connectors called RJ-45 bits. The individual wires are colour coded and are visible in the RJ-45 connector from the top. The most common sequence is 1. green-white 2. green 3. orange-white 4. blue 5. blue-white 6. orange 7. brown-white 8. brown. This is the setup on both ends for what is called a straight-thru cable. The only wires actually used are positions 1, 2, 3 and 6. When you want to connect 2 ethernet cards directly without use of a hub or switch you require a cable that is crossed-over or a cross-over cable. This is called so because positions 1 and 3 and 2 and 6 are crossed, so the end of the crossed end looks like this 1. orange-white 2. orange 3. green-white 4. blue 5. blue-white 6. green 7. brown-white 8. brown. The most common type of cabling for ethernet is category 5 cabling although there is category 5e now for gigabit. To attach the RJ-45 bits to the cabling a special tool called a RJ-45 crimper is used. Cheap version s are about $30 (CA) at cabling surplus stores.