Network Connectivity Devices & Concepts

A network gateway is an inter-networking system capable of joining together two networks that use different base protocols. A network gateway can be implemented completely in software, completely in hardware, or as a combination of both.

A bridge device filters data traffic at a network boundary. Bridges reduce the amount of traffic on a LAN by dividing it into two segments.

Network repeaters regenerate incoming electrical, wireless or optical signals. With physical media like Ethernet or Wi-Fi data transmissions can only span a limited distance before the quality of the signal degrades. Repeaters attempt to preserve signal integrity and extend the distance over which data can safely travel.

The client–server model of computing is a distributed application structure that partitions tasks or workloads between the providers of a resource or service, called servers, and service requesters, called clients.

A name server consists of a program or computer server that implements a name-service protocol. It maps a human-recognizable identifier to a system-internal, often numeric, identification or addressing component. The most prominent types of name servers in operation today are the name servers of the Domain Name System (DNS).

The most important function of these DNS servers is the translation (resolution) of humanly memorable domain names and hostnames into the corresponding numeric Internet Protocol (IP) addresses.

Web server can refer to either the hardware (the computer) or the software (the computer application) that helps to deliver content that can be accessed through the Internet.

The most common use of Web servers is to host Web sites but there are other uses like data storage or for running enterprise applications.

A proxy server is a server (a computer system or an application) that acts as an intermediary for requests from clients seeking resources from other servers. A client connects to the proxy server, requesting some service, such as a file, connection, web page, or other resource, available from a different server. The proxy server evaluates the request according to its filtering rules.

Packet switching is a digital networking communications method that groups all transmitted data into suitably sized blocks, called packets.

Eg:- Cellular communication services, circuit switching is characterized by a fee per time unit of connection time, even when no data is transferred, while packet switching is characterized by a fee per unit of information.

- Internet communication.

Two major packet switching modes exist;

(1) Connectionless packet switching.

(2) Connection-oriented packet switching.

Circuit switching is a telecommunications technology by which two network nodes establish a dedicated communications channel (circuit) before the nodes may communicate. The circuit remains connected for the duration of the communication session.

Eg: PSTN (Public Switched Telephone Network)