WHAT ARE THE TYPES OF CABLE?

TYPES OF CABLE

1. Twisted-pair cable

• Is the most common type of cable.
•  Have eight individual copper wires bundled together and covered with an insulating  material.
•  The copper wire is always color-coded with a plastic insulation and they are twisted in pairs for a total of four pairs.

a.  STP (Shielded Twisted Pair)

• Often used in “noisy” environments where a shield of metallic foil is wrapped around each of the wire pairs, with an additional overall shielding to protect against excessive electromagnetic interference.

b. UTP (Unshielded Twisted Pair)

•  Is the most common form of twisted pair wiring. It is less expensive and easier to work with than STP.

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2. Coaxial Cable

•  the standard media used by cable TV operators.
• it consists of a plastic insulator that separates the solid copper inner conductor and the woven, copper braid outer conductor.

3. Fiber-optic Cable

• has a reflective coating that allows light beams to travel without outer interference.

WHAT IS A NETWORK ADDRESS?

WHAT IS A NETWORK ADDRESS? 

• A network address is a set of numbers called "octets" that identifies any network device(computer, printer, camera, router, switch, etc.), which we will generally refer to as a host in a network. It is more commonly known as Internet Protocol (IP) address.

• It can be compared to the physical address that we use for our homes, which uniquely identifies it from the rest of the homes in our neighborhood, town,city,province,country and the whole wide world.

• But unlike or home addresses,which points to a specific geographical location, an IP address is just logical address that points to which network group a particular network device(host) belongs.

• It doesn't matter where a particular host is located geographically, for as long as it has a valid IP address, other hosts can communicate with it.

IPv4

• IPv4 address is the specific version or type of IP address that we all came to know and become accustomed with.

• Whenever we speak of IP address, we refer to IPv4 addresses used in the Internet in order for us to have an easier time to understand what it is.

• An IP address is a series of four sets of numbers called "octets".

• For easier readability, we write this set of octets in what we call a "dotted decimal" notation:e.g., 192.168.1.120 or 74.125.224.72(Google.com).

• Each octet in the series is a decimal value of 8 bits of binary number or 1 byte. Thus, the binary 00000000 is equal to 0 and 11111111 is equal to 255.

• So each octet will have a value range of 0-255 only. Having this in mind, it would mean that there will only be a little less than 4.3 billion possible IP addresses available for each network host worldwide.

• The net ID is indicated by the first three high order bits of the first octet and is categorized into different classes.

• The 3 most common classes are classes A,B and C. Classes D and E are rarely used,especially among end-users like you and me.

• Classifying IP addresses allows for easy searching through different networks. It also allows for effective management of hosts in a particular network.

• Class A IP addresses are assigned to organizations with a large number of hosts connecting to the network

• Class B is for medium-sized network organizations

• Class C is usually for networks run by small organizations or offices.

• Allocation of IP addresses is done according to the size of network, which is determined by the number of hosts.

Reserved IP Addresses

• In some organizations, not all computers are directly connected to the Internet. Usually, these computers are connected through a local network and only connect to the Internet through one computer (usually a proxy or a getaway)

• There is no need to reserve an IP address for the computers in these kinds of networks.

• Certain IP address blocks are reserved for each network class to make sure that these addresses do not conflict with IP addresses used in the Internet.

• Gateway is a node that serves as the access point on a network- typically a router.

• Subnet Masks are used to set or assign a logical network within a network. This way, administrators are able to extend the network size by creating logical or sub networks equivalent to as many as the number of bits it borrowed from the host ID side of the IP address.

DCHP AND DNS

• DCHP or Dynamic Host Configuration Protocol is a system built in every server operating system that allows computers or hosts to join IP-based networks with minimal manual configuration. It assigns an Ip address from a pool that is allotted to it.

• Because of DHCP, we no longer need to figure what IP address to use in order to connect and communicate with other hosts in the network. It also managed the release and renewal of IP addresses assigned to a particular host.

• DCHP is present in all servers and some network devices like gateways and routers in an IP-based network. Whenever you connect a computer or host on a network, it broadcasts a signal or communication alerting all other hosts in the network.

• DNS(Domain Name Server) is responsible for mapping out and navigating hosts on the internet based on names. These names are referred to as URLs (Uniform Resource Locator). This is naming convention for the different hosts(websites) on the Internet.

• Each of these URLs with known domain names (Google,Yahoo!, Facebook,Speedtest) is representing a specific IP address that points to the computer hosting the site.

WHAT IS THE DIFFERENCE BETWEEN STRAIGHT THROUGH AND CROSSOVER

Straight and Crossover Cable
• Examples of common Ethernet network cables are straight and crossover cables. These Ethernet network cable are made of four pairs of high performance cables consisting of twisted pair conductors used for data transmission.

       •       The ends of the cable are called RJ-45 connectors.

• Straight and crossover cables can be Cat3,Cat5, Cat5e, or Cat 6 UTP cable; the main difference is that each type will have different wire arrangements and purpose.

Straight Cable

• You usually use straight cable to connect different type of devices. This type of cable will be used most of the time and can be used to:
1. Connect a computer to a switch/hub's normal port.
2. Connect a computer to a cable/DSL modem's LAN port.
3. Connect a router's WAN port to a cable/DSL modem's LAN port.
4. Connect a router's LAN port to a switch/hub's uplink port. (normally used for expanding network)
5. Connect 2 switches/hubs with one of the switch/hub using an uplink port and the other one using normal port.

Crossover Cable

• Sometimes you will use crossover cable;its usually used to connect same type of devices. A crossover cable can be used to:
1. Connect 2 computers directly.
2. Connect a router's LAN port to a switch/hub's normal port. (normally used for expanding network)
3. Connect 2 switches/hubs by using normal port in both switches/sides.

• Generally, a straight-through cable is used to connect end node devices to a networking device. On the other hand, a cross over cable is used to connect same type of devices (e.g., PC-PC, switch-switch, router-switch [for expanding a network])