One of the more interesting facilities of Ethernet is it's ability to communicate over various types of media. An Ethernet NIC can come with several types of ports to connect to several different types of cabling which make Ethernet one of the most versatile types of networking systems available. Some NIC's can communicate with several networks through different ports and Media types. In 10 Base-T systems only one PHY is required. In systems that use Fast Ethernet and are connected to different media a PHY is required for each one. The types of connectors and cabling used on most Ethernet systems are as follows.

RJ-45 The RJ-45 connector is one of the most common type of media coupling used for Ethernet. It is an eight-wire connector using UTP (unshielded twisted pair) cable. It can be used for 10Base-T, (Category 3, 4, and 5 cable)100Base-T4 (Category 3, 4 and 5) and 100Base-TX (Category 5, or STP). Note that Category 5, is recommened for Fast Ethernet, 100base T.

AUIThe AUI (attachment unit interface) connector is used with Thicknet. It connects the NIC with an Ethernet transceiver (part of the PHY). Used with 10Base-T NICs and uses coaxial cable.

BNCThe BNC (British Naval Connector) is used for 10Base-2 (Cheapernet) Networks. Unlike the AUI type of connection a network that uses BNC connectors have the transceiver integrated into the NIC. The BNC connects to a thinner type of coaxial cable than an AUI connector.

DB9This type of connector is use with STP (shielded twisted pair) cabling. IBM Type-1 STP is the most common of the IBM cable specifications. The IEEE does not support the IBM Type-1 data connector but has included the DB9 as a data connector for STP. STP has the attributes of coaxial cable and twisted-pair cable being encased inside an external aluminum-foil or woven-copper shield helps reduce electrical interference. This kind of connector can be used for 100Base-TX NICs.

SC SC Connectors (straight connect) is used for fiber optic cable. The SC connector is actually two plugs, one for receiving data and one for transmitting. This kind of connector can be used with 10Base-F and 100Base-FX NICs.

ST ST Connectors (straight twist) is also used for fiber optic cable. Its attributes are similar to the SC connector but is more expensive.