Computer Networking Further more...

        

Main Network Hardware Components

Ø Hub– electronic device (with a number of ports) used in a LAN to link groups of computers.

Ø Repeaters (also called amplifiers) – electronic devices that receive signals and amplify and send them along the network.

Ø Routers - electronic devices used to ensure messages are sent to their intended destinations.

Ø Gateway– consists of hardware and/or software that allows communications between dissimilar networks.

Ø Bridge– consists of hardware and/or software that allows communication between two similar networks.

Why used Interconnect?

Ø To connect two LANs with different protocols.

Ø To connect a LAN to the Internet.

Ø To break a LAN into segments to relieve traffic congestion.

Ø To provide a security wall between two different types of users.

Ø To connect WLAN to LAN

Ø Remote Access.

Interconnection within similar networks or dissimilar networks done via different devices

ü Computers within a LAN are often connected using a hub.

ü LAN to LAN connections are often performed with a bridge.

ü Segments of a LAN are usually connected using a switch.

ü LAN to WAN connections are usually performed with a router.

Networks are usually classified using three properties:

Ø Topology

Ø Protocol

Ø Architecture

Ø Topology

Refers to the way computers and peripherals are configured to form networks. There are several topologies use in networking.

Star Topology

The star topology is a popular method of connecting the cabling in a computer network. In a star, each device connects to a central point via a point-to point link.

 

Ring Topology

The Ring Topology is a physical, closed loop consisting of point-to-point links. It receives a transmission from the previous node and amplifies it before passing it on.

   

Bus Topology

In a Bus topology, all devices attach to the same transmission medium. The medium has a physical beginning and end. All buses are implemented using electrical cable, usually coax, and the ends of the cable must be terminated with a terminating resistor that matches the impedance of the cable. The bus is considered a multipoint system because all devices tap into the same backbone cable.

Hybrid Topology

The Hybrid topology scheme combines multiple topologies into one large topology. The hybrid network is common in large wide area networks.

 

Ø Protocol

A protocol is simply an agreed-on set of rules and procedures for transmitting data between two or more devices.

Ø Architecture

Network architecture refers to the way a network is designed and built. There are two major types.

Peer-to-peer architecture– Computers connect with each other in a work-group to share files, printers, and Internet access. This is used to connect a small number of computers.

Client/server architecture– sends information from a client computer to a server, which then relays the information back to the client computer, or to other computers on the network.