What are the Types of Cables?

What are the TYPES OF CABLES?

• Despite advances in wireless technologies, many computer networks in the 21st century still rely on cables as a physical medium for devices to transfer data. Several standard types of network cables exist, each designed for specific purposes.

 TYPES OF CABLES

 1. TWISTED-PAIR CABLES 

→  A type of cable that consists of two independently insulated wires twisted around one another. The use of two wires twisted together helps to reduce crosstalk and electromagnetic induction. While twisted-pair cable is used by older telephone networks and is the least expensive type of local-area network (LAN) cable, most networks contain some twisted-pair cabling at some point along the network. Other types of cables used for LANs include coaxial cables and fiber optic cables.

  

→ Two primary types of twisted pair cable industry standards have been defined: Unshielded Twisted Pair (UTP) and Shielded Twisted Pair (STP).

a. SHIELDED TWISTED PAIR (STP)

→ Often abbreviated STP, a type of copper telephone wiring in which each of the two copper wires that are twisted together are coated with an insulating coating that functions as a ground for the wires. The extra covering in shielded twisted pair wiring protects the transmission line from electromagnetic interference leaking into or out of the cable. STP cabling often is used in Ethernet networks, especially fast data rate Ethernets.

b. UNSHIELDED  TWISTED PAIR (UTP)

→ UTP stands for Unshielded Twisted Pair cable. UTP cable is a 100 ohm copper cable that consists of 2 to 1800 unshielded twisted pairs surrounded by an outer jacket. They have no metallic shield. This makes the cable small in diameter but unprotected against electrical interference. The twist helps to improve its immunity to electrical noise and EMI.

 

2. COAXIAL CABLE

→ Invented in the 1880s, "coax" was best known as the kind of cable that connected television sets to home antennas. Coaxial cable is also a standard for 10 Mbps Ethernet cables. When 10 Mbps Ethernet was most popular, during the 1980s and early 1990s, networks typically utilized one of two kinds of coax cable - thinnet (10BASE2 standard) or thicknet (10BASE5). These cables consist of an inner copper wire of varying thickness surrounded by insulation and another shielding. Their stiffness caused network administrators difficulty in installing and maintaining thinnet and thicknet.

3. FIBER-OPTIC CABLE

→ An optical fiber cable, also known as a fiber optic cable, is an assembly similar to an electrical cable, but containing one or more optical fibers that are used to carry light. The optical fiber elements are typically individually coated with plastic layers and contained in a protective tube suitable for the environment where the cable will be deployed. Different types of cable are used for different applications, for example long distance telecommunication, or providing a high-speed data connection between different parts of a building.

 

 Difference between Straight-through cable and Cross-over cable

• Ethernet cables can be wired as straight through or crossover. The straight through is the most common type and is used to connect computers to hubs or switches. They are most likely what you will find when you go to your local computer store and buy a patch cable. Crossover cable is more commonly used to connect a computer to a computer and may be a little harder to find since they aren’t used nearly as much as straight through cable. Then, what’s the difference between them? Difference between straight through and crossover cables will be introduced in this blog.

Straight Through Cable

→ A straight through cable is a type of twisted pair cable that is used in local area networks to connect a computer to a network hub such as a router. This type of cable is also sometimes called a patch cable and is an alternative to wireless connections where one or more computers access a router through a wireless signal. On a straight through cable, the wired pins match. Straight through cable use one wiring standard: both ends use T568A wiring standard or both ends use T568B wiring standard. The following figure shows a straight through cable of which both ends are wired as the T568B standard.

 Cross-over Cable

→ An Ethernet crossover cable is a type of Ethernet cable used to connect computing devices together directly. Unlike straight through cable, crossover cables use two different wiring standards: one end uses the T568A wiring standard, and the other end uses the T568B wiring standard. The internal wiring of Ethernet crossover cables reverses the transmit and receive signals. It is most often used to connect two devices of the same type: e.g. two computers (via network interface controller) or two switches to each other.

•  Usually, straight through cables are primarily used for connecting unlike devices. And crossover cables are use for connecting unlike devices alike devices.

Conclusion:

⇒ Straight through and crossover cables are wired differently from each other. One easy way to tell what you have is to look at the order of the colored wires inside the RJ45 connector. If the order of the wires is the same on both ends, then you have a straight through cable. If not, then it’s most likely a crossover cable or was wired wrong. At present, the straight through cable is much more popular than crossover cable and is widely used by people.

Sources:
https://www.lifewire.com/introduction-to-network-cables-817868
https://www.webopedia.com/TERM/T/twisted_pair_cable.html 
https://www.webopedia.com/TERM/S/shielded_twisted_pair.html
https://www.fiberoptics4sale.com/blogs/archive-posts/95046918-what-is-unshielded-twisted-pair-utp-cable
https://en.wikipedia.org/wiki/Optical_fiber_cable 
http://www.cables-solutions.com/difference-between-straight-through-and-crossover-cable.html

What are the types of Network Topology?

NETWORK TOPOLOGY

• A network topology is the arrangement of a network, including its nodes and connecting lines. There are two ways of defining network geometry: the physical topology and the logical (or signal) topology.
• Network topology is the arrangement of the elements (links, nodes, etc.) of a communication network. Network topology can be used to define or describe the arrangement of various types of telecommunication networks, including command and control radio networks, industrial fieldbusses, and computer networks.
• Network Topology is the schematic description of a network arrangement, connecting various nodes(sender and receiver) through lines of connection.

TYPES OF NETWORK TOPOLOGY

BUS TOPOLOGY

⇒  Bus topology is a network type in which every computer and network device is connected to              single cable. When it has exactly two endpoints, then it is called Linear Bus topology.

RING TOPOLOGY
⇒ It is called ring topology because it forms a ring as each computer is connected to another                  computer, with the last one connected to the first. Exactly two neighbours for each device.

STAR TOPOLOGY
⇒ In this type of topology all the computers are connected to a single hub through a cable. This           hub is the central node and all others nodes are connected to the central node. 

MESH TOPOLOGY
⇒  It is a point-to-point connection to other nodes or devices. All the network nodes are                        connected to each other. 

HYBRID TOPOLOGY
⇒  It is two different types of topologies which is a mixture of two or more topologies. For                      example if in an office in one department ring topology is used and in another star topology            is used, connecting these topologies will result in Hybrid Topology (ring topology and star                topology).   

Sources:

https://whatis.techtarget.com/definition/network-topology

https://en.wikipedia.org/wiki/Network_topology

https://www.studytonight.com/computer-networks/network-topology-types

What are the types of Computer Network?

What are the types of Computer Network?

• One way to categorize the different types of computer network designs is by their scope or scale. For historical reasons, the networking industry refers to nearly every type of design as some kind of area network.

Common types of area networks are:

1. Personal Area Network (PAN)

       ⇒  A personal area network (PAN) is a computer network for interconnecting devices centered                on an individual person's workspace. A PAN provides data transmission amongst devices                      such as computers, smartphones, tablets and personal digital assistants.

       ⇒  PANs can be used for communication amongst the personal devices themselves, or for                          connecting to a higher level network and the Internet (an uplink) where one master device                      takes up the role as gateway. 

       ⇒  A PAN may be carried over wired computer buses such as USB.

      2. Local Area Network (LAN)

• A local area network (LAN) is a computer network that interconnects computers within a limited area such as a residence, school, laboratory, university campus or office building.
• By contrast, a wide area network (WAN) not only covers a larger geographic distance, but also generally involves leased telecommunication circuits.

     3. Metropolitan Area Network (MAN)

         →  A metropolitan area network (MAN) is a computer network that interconnects users with                     computer resources in a geographic area or region larger than that covered by even a                           large local area network (LAN) but smaller than the area covered by a wide area                                     network (WAN). 

        →   The term MAN is applied to the interconnection of networks in a city into a single larger                          network which may then also offer efficient connection to a wide area network.It is also used                  to mean the interconnection of several local area networks in a metropolitan area through                     the use of point-to-point connections between them.

      4. Wide Area Network (WAN)

• A wide area network (WAN) is a telecommunications network or computer network that extends over a large geographical distance/place. Wide area networks are often established                     with leased telecommunication circuits.

Sources/Links:

https://www.lifewire.com/lans-wans-and-other-area-networks-817376

https://en.wikipedia.org/wiki/Personal_area_network

https://en.wikipedia.org/wiki/Local_area_network

https://en.wikipedia.org/wiki/Metropolitan_area_network

https://en.wikipedia.org/wiki/Wide_area_network