What is Network?
– When two or more nodes (element of network ) are interconnected.
Base on Geographical location :
a) LAN ( Local Area Network)
b) MAN ( Metropolitan Area Network)
c) WAN ( wide Area Network)
Others Networks are : HAN ( Home Area Network), PAN ( Personal Area Network), CAN ( Controller Area Network), BAN (Body Area Network)
BAN: A Body Area Network is formally defined by IEEE 802.15 as, “a communication standard optimized for low power devices and operation on, in or around the human body (but not limited to humans) to serve a variety of applications including medical, consumer electronics / personal entertainment and other“.
In a short, a Body Area Network is a system of devices in close proximity to a persons body that cooperate for the benefit of the user.
Connecting Device for Networking :
1. Inter-connection Device ( such as Network Interface card, Repeater, Hub, Bridge , Switch , Router)
2. Transmission Medium (A Transmission medium is a material substance that can propagate energy waves. For example, the transmission medium for sounds is usually air, but solids and liquids may also act as transmission media for sound. For Example : Electromagnetic Radiation can be transmitted through an Optical medium such as Optical Fiber, or through twisted pair wires, coaxial cable, or dielectric-slab wave-guides.)
3. Communication protocol ( A communication protocol is a system of digital rules for data exchange within or between computers)
Inter-connection Device , Short Description :
a) Network Interface Card (NIC) is commonly known as LAN Card . Every LAN Card has a globally unique physical Address or MAC (media access control address) address.
A media access control address (MAC address) is a unique identifier assigned to network interfaces for communications on the physical network segment. MAC addresses are used as a network address for most IEEE 802network technologies, including Ethernet. Logically, MAC addresses are used in the media access control protocol sub layer of the OSI reference Model.
Every MAC address is 48 bits long. for example : -5a-bc-6d-42-ab-52
-5a-bc-6d : First 24 bits represent vendor ID or Manufacturer ID
-42-ab-52 : last 24 bits represent product ID
b) Repeater : A repeater mainly forward single source to destination. In Telecommunication, a repeater is an electronic device that receives a signal and re-transmits it at a higher level or higher power, or onto the other side of an obstruction, so that the signal can cover longer distances.
c) HUB: An Ethernet hub, active hub, network hub, repeater hub, multiport repeater or hub is a device for connecting multiple Ethernet devices together and making them act as a single network segment . It has multiple input/output (I/O) ports, in which a signal introduced at the input of any port appears at the output of every port except the original incoming.
A hub works at the Physical Layer (Layer -1 ) of the OSI Model . Repeater hubs also participate in collision detection, forwarding a jam signal to all ports if it detects a collision.
d) Switch : A network switch (sometimes known as a switching hub) is a computer networking device that is used to connect devices together on a computer network by performing a form of packet switching. A switch is considered more advanced than a Hub because a switch will only send a message to the device that needs or requests it, rather than broadcasting the same message out of each of its ports.
A switch is a multi-port network bridge that processes and forwards data at the data link layer (layer 2) of the OSI Model. Some switches have additional features, including the ability to route packets. These switches are commonly known as layer-3 or multilayer switches.
In switch , RAM mainly maintain MAC address table.
e) Router : Routers are small physical devices that join multiple networks together. Technically, a router is a Layer 3 gateway device, meaning that it connects two or more networks and that the router operates at the network layer of the OSI model.
Routers perform the “traffic directing” functions on the Internet. A data packet is typically forwarded from one router to another through the networks that constitute the internetwork until it reaches its destination node.
Switches create a network. Routers connect networks. A router links computers to the Internet, so users can share the connection. A router acts as a dispatcher, choosing the best path for information to travel so it’s received quickly.
Thank you
Momataj Momo
My Networking Learning "ABC" 