Cisco CCNA 200-301 – Cabling Types: Coax, Twisted Pair, Fiber

Twisted Pair cable has pairs of wires with each pair twisted to eliminate electromagnetic interference and prevent crosstalk; each pair forms a circuit that can transmit data. At each end of the cable RJ-45 connectors are installed, The RJ-45 is an eight-wire connector used commonly to connect computers onto an Ethernet local-area network (LAN).

There are two sub-categories of Twisted Pair Cables as mentioned below

•  Unshielded Twisted Pair Cable (UTP)
•  Shielded Twisted Pair Cable (STP)

Unshielded Twisted Pair Cable (UTP) is the most common type of cable used in networks. Almost all Ethernet LANs are built using UTP cables. UTP cables are thin and flexible and very cost-effective which makes them the ideal choice for Ethernet cabling. The EIA/TIA (Electronic Industry Association/Telecommunication Industry Association) has established standards of UTP and rated various categories of wire some of which are shown below.

The figure below shows an Unshielded Twisted Pair Cable

Shielded Twisted Pair Cable (STP) wraps each pair of wire in a metallic foil and further wraps all four pairs if wires in a metallic braid or foil, this further reduces the noise both within the cable from outside the cable. STP cable is more expensive then UTP cable and is much more difficult to install and manage. It also requires grounding at both ends of the metallic shield.

The figure below shows a Shielded Twisted Pair Cable

Coxial cable is the most popular cable in the cable television industry, a coaxial cable consists of a copper conductor which is surrounded by insulation material, over the insulation material is copper braid or foil that acts both as the second wire in the circuit and as a shield for the inner conductor thereby protecting it from interference. The coaxial cable is difficult to install and manage but it can support much greater cable lengths.

The figure below shows a coaxial cable.

There are two types of coaxial cable

•  Thinnet: It has a diameter of 0.25 inches and is relatively easy to install as compared to the Thicknet cable. It was used previously used in Ethernet networks but since the cable required grounding and many problems were faced due to improper grounding it is no longer used in Ethernet networks.
• Thicknet: It has a diameter of 0.38 inches which makes it a better conductor, this cable can carry a signal long distances before the signal quality degrades.

Fiber-Optic cable is made up of glass and plastic fibers surrounded by several layers of protective materials. Fiber-optic cables are much more expensive than twisted-pair and coaxial cables. Fiber-optic cables are immune to EMI and can run small and large distances depending upon the type of cable. Fiber-optic cables support very high bandwidth which makes them the preferred choice of cables when high speed connectivity is required.

There two types of fiber optic cables

• Single-Mode: It has as single stand of glass fiber, with a small core and supports one mode of transmission. Single mode fiber optic cable can run longer distances but it is more expensive than multi-mode fiber.
• Multi-Mode: It has a bigger core and supports multiple propagation paths and modes. Multi-mode fiber is used for small to medium distances

The figure below shows a fiber-optic cable.

This brings us to the end of this lesson in which we learned different types of cables used to build networks, we also covered the benefits and shortcoming of each cable type.