Communication (AS Level) flashcards

2.1 Networks including the internet

What is the difference between the client-server and peer-to-peer models?

Client-server: dedicated servers provide services (files, authentication, printing) to clients. Peer-to-peer: all computers have equal status and each acts as both client and server.

What is the difference between a thin client and a thick client?

A thin client relies heavily on the server for processing. A thick client does most of its processing locally.

How do the bus, star and mesh topologies differ?

Bus: one shared line all devices connect to. Star: every device connects to a central switch, so a faulty link is easy to isolate. Mesh: many interconnections, so there are alternative routes and high resilience.

What does CSMA/CD do on an Ethernet network?

Carrier Sense Multiple Access / Collision Detection: a device checks the medium is free before transmitting; if a collision is detected, each device waits a random time before trying again.

What is the difference between the internet and the World Wide Web?

The internet is the global network of interconnected networks (the infrastructure). The WWW is the collection of linked web pages and resources accessed over the internet using HTTP.

What does DNS do?

The Domain Name System translates the domain name in a URL into the IP address that is used to route the request.

What is the difference between a static and a dynamic IP address?

Static: fixed, does not change (suits a web server that must always be found). Dynamic: assigned from a pool each time a device connects, usually by DHCP, so addresses can be reused.

What is the difference between a switch and a router?

A switch forwards data between devices within one network. A router forwards packets between different networks, such as a LAN and the internet.