Basic Network Concepts (Part 4). Network Media and Connectors. Fiber -Optic Cable
Network Media and Connectors • Fiber-Optic Cable • Fiber-optic cabling is unlike coax and twisted-pair, because both of those types have a copper wire that carries the electrical signal. Fiber-optic cables use optical fibers that carry digital data signals in the form of modulated pulses of light. An optical fiberconsists of an extremely thin cylinder of glass, called the core, surrounded by a concentric layer of glass, known as the cladding.
Network Media and Connectors • Fiber-Optic Cable • There are two fibers per cable: • one to transmit • one to receive • The core also can be an optical-quality clear plastic, and the cladding can be made up of gel that reflects signals back into the fiberto reduce signal loss. • There are two types of fiber-optic cables: • Single-mode fiber • Uses a single ray of light, known as a mode, to carry the transmission over long distances. • Multimode fiber • Uses multiple rays of light (modes) simultaneously, with each ray of light running at a different reflection angle to carry the transmission over short distances.
Network Media and Connectors • Fiber-Optic Cable • Fiber-optic cable supports up to 1000 stations and can carry the signal up to and beyond 2 kilometers • Fiber-optic cables are also highly secure from outside interference, such as radio transmitters, arc welders, fluorescent lights, and other sources of electrical noise. • Fiber-optic cable is by far the most expensive of these cabling methods, and a small network is unlikely to need these features.
Network Media and Connectors • Fiber-Optic Cable • Two major connector types: • the straight-tip (ST) connector • is based on the BNC-style connector but has a fiber-optic cable instead of a copper cable. • the subscriber (SC) connector • is square and somewhat similar to an RJ-45 connector. • Regardless of the connector type, the fiber-optic cable still functions at the same speed, which is typically 1000 Mbps and faster.
Network Media and Connectors • Coaxial Connectors • The BNC-T connector • is used to connect to coax cable from either side (so that the cable length can continue on), while a third end of the connector tees out to have a cable length connect to the network card on the client machine.
Network Media and Connectors • Coaxial Connectors • The BNC-T 50-ohm terminator
Network Media and Connectors • Twisted-Pair Connectors • Aside from RJ11 and RJ45, there are also barrelconnectors, which are female connectors on both ends that allow you to join two cable lengths together and reach greater distances, not exceeding 100 meters.
Network Media and Connectors • Other Connectors • There are a number of additional connector types that you will come across in networking environments, some of which are listed here: • F-type connector • Another connector style for coax cabling, it is the same connector style that runs to your TV. • Fiber local connector (LC) and mechanical-transfer registered jack (MT-RJ) • Additional fiber-optic connector types that are similar to the registered jack and fiber SC shape. The Fiber LC is the preferred connector of the two for communications exceeding 1 Gbps due to its small form factor.
Network Media and Connectors • Other Connectors • Universal serial bus (USB) • A high-speed serial bus that supports 127 devices in the chain. USB uses a standard connector type that is used by most devices, including mice, printers, network cards, digital cameras, and flash drives. • There are two USB standards: USB 1.1, which has a transfer rate of 12 Mbps, and USB 2.0, which has a transfer rate of 480 Mbps. • There are two standard USB connectors, Type A and Type B. Type A connectors connect to the computer, whereas Type B connectors connect to the device.
Network Media and Connectors • Other Connectors • IEEE 1394 (FireWire) • An ultra-high-speed bus that supports 63 devices in the chain and is ideal for real-time applications and devices such as for video. FireWire has two standards: 1394a, which has a transfer rate of 400 Mbps, and 1394b, which has a transfer rate of 800 Mbps. • RS-232 • The standard for serial connections using the serial port on a computer. The serial port was a popular way to achieve a point-to-point connection between two hosts or was used for modems. The RS-232 standard defines a transfer rate of 20,000 bits per second, but serial devices support higher transfer rates.
Network Media and Connectors F-Type MT-RJ 1394B 1394A