Network+connectivity

Network connectivity  Back Until recently, cables were the only medium used to connect devices on networks. A wide variety of networking cables are available. Coaxial and twisted-pair cables use copper to transmit data. Fiber-optic cables use glass or plastic to transmit data. These cables differ in bandwidth, size, and cost. You need to know what type of cable to use in different situations to install the correct cables for the job. You also need to be able to troubleshoot and repair problems that you encounter.

Twisted-Pair

Twisted-pair is a type of copper cabling that is used for telephone communications and most Ethernet networks. A pair of wires forms a circuit that can transmit data. The pair is twisted to provide protection against crosstalk, which is the noise generated by adjacent pairs of wires in the cable. Pairs of copper wires are encased in color-coded plastic insulation and twisted together. An outer jacket protects the bundles of twisted pairs. There are two basic types of twisted-pair cables:


 * **Unshielded twisted-pair (UTP)** – Cable that has two or four pairs of wires. This type of cable relies solely on the cancellation effect produced by the twisted-wire pairs that limits signal degradation caused by electromagnetic interface (EMI) and radio frequency interference (RFI). UTP is the most commonly used cabling in networks. UTP cables have a range of 100m




 * **Shielded twisted-pair (STP)** – Each pair of wires is wrapped in metallic foil to better shield the wires from noise. Four pairs of wires are then wrapped in an overall metallic braid or foil. STP reduces electrical noise from within the cable. It also reduces EMI and RFI from outside the cable.


 * Coaxial Cable

Coaxial cable is a copper-cored cable surrounded by a heavy shielding. Coaxial cable is used to connect computers in a network. There are several types of caxial cable:


 * **Thicknet or 10BASE5** – Coax cable used in networks and operated at 10 Mbps with a maximum length of 500 m (1640.4 ft)
 * **Thinnet 10BASE2** – Coax cable used in networks and operated at 10 Mbps with a maximum length of 185 m (607 ft)
 * **RG-59** – Most commonly used for cable television in the U.S.
 * **RG-6** – Higher quality cable than RG-59, with more bandwidth and less susceptibility to interference



Fiber-Optic Cable

An optical fiber is a glass or plastic conductor that transmits information using light. Fiber-optic cable has one or more optical fibers enclosed in a sheath or jacket. Because it is made of glass, fiber-optic cable is not affected by EMI or RFI. All signals are converted to light pulses to enter the cable, and converted back into electrical signals when they leave it. This means that fiber-optic cable can deliver signals that are clearer, can go farther, and have greater bandwidth than cable made of copper or other metals.



<span style="font-family: 'Comic Sans MS',cursive; font-size: 14pt;">Summary

<span style="font-family: Georgia,serif; font-size: 120%;">Cables are used to connect devices on networks. Most of cables use copper to transmit data, but there are types use light instead of copper. These are types of cables that are different in their ability to send the data.

<span style="font-family: Georgia,serif; font-size: 120%;">Twisted-pair

<span style="font-family: Georgia,serif; font-size: 120%;">It used for telephone communication and Ethernet networks. The twisting of pair wires protects from radio waves and crosstalk. There are two types of twisted-pair cables: <span style="font-family: Georgia,serif; font-size: 120%;">Ø Unshielded twisted-pair (UTP): it is used a lot today. It has two or four pair of wires. It also has a range of 100 m (328 ft). <span style="font-family: Georgia,serif; font-size: 120%;">Ø Shielded twisted-pair (STP): each two or four pair of wires is wrapped with metallic foil for better protection from cross talk. It also reduces Electromagnetic interface (EMI) and radio frequency interface (RFI) from outside the cable

<span style="font-family: Georgia,serif; font-size: 120%;">Coaxial cable <span style="font-family: Georgia,serif; font-size: 120%;">It contains a copper wire in the core surrounding by heavy shielding. There are types of coaxial cables such as: Thicknet (10BASE5), Thinnet (10BASE2), RG-59 and RG-6.

<span style="font-family: Georgia,serif; font-size: 120%;">Fiber-optic cable <span style="font-family: Georgia,serif; font-size: 120%;">It is a glass or plastic conductor that carries out light not electricity. Radio waves do not interface with light signals. Therefore, fiber-optic is not affected by (EMI) or (RFI). In addition, it is very fast and secure to use in networking.

<span style="font-family: 'Comic Sans MS',cursive; font-size: 12pt;">Resource

<span style="font-family: Georgia,serif; font-size: 120%;">CISCO Networking Academy Program Website