Karteikarten
The structure of the Internet
Karten in diesem Stapel (42)
- 1What type of software is required to access a web site?Browser software
- 2What is the ISP role? (Internet service provider)To provide access to the Internet to individuals/organisations.
To provide electronic mail boxes.
To act as hosts for web pages. - 3What is the primary role of an ISP?Provide internet access.
- 4What's a protocol?It's a set of rules that allows communication.
E.g. HTTP, FTP, POP, SMTP - 5What's a telnet?It's a text-based protocol that can be used to manage a remote machine e.g. web site.
- 6What does POP3 stand for and what does it mean?Post Office Protocol
Downloading personal emails from a web mail server. - 7What does SMTP stand for and what does it do?Simple Mail Transfer Protocol
Sends email messages. - 8What does FTP do?Uploading files to a web server.
- 9Give a use for each of the protocols listed below.FTP: to upload/download files
POP3: to retrieve/fetch email = to check for new emails
HTTPS: acces your online bank account using a web browser - 10State two reasons why the technician uses remote management software from her computer rather than going to the actual servers.Servers might be in another room/site/cupboard/inaccessible.
Servers can be managed outside of work hours/from anywhere.
It would be quicker and more convenient to manage from her machine than visit the servers. - 11Define world wide web.Collection of data files using Hypertext Mark-up Language.
- 12What is the internet?World-wide collection of networks/computers using the same protocol (TCP/IP)
- 13Explain the differences between the World Wide Web and the Internet.WWW:
- a system of hypertext documents
- accessed via the internet
- uses HTTP protocol
The Internet:
- a network of interconnected computer networks
- using a globally unique address space
- using TCP/IP protocol - 14What's the Intranet?Network providing Internet facilities within an organisation.
- 15Name two similarities between an Intranet and the Internet.Both use the same protocol (Both use TCP/IP).
Both use the same software (web browser).
Both have a similar purpose (share information/data/resources).
Both have accessed through the use of a URL.
Both are client-server based. - 16What does URL stand for and what does it consist of?Uniform Resource Locator
Protocol used + address of resource - 17Structure of the web address
- 18Describe the three labelled parts of this URL: ftp://ftp.fileden.org.uk/pascal/source.pasftp - protocol used
ftp.fileden.org.uk - fully qualifies domain name
pascal/source.pas - path name - 19Give an example of a URL.http://www.bbc.co.uk/history
- 20Below is the URL of a web page. http://www.aqa.org.uk Explain what each of these parts of the URL mean.http:// - (Hypertext transfer protocol) this is the protocol that will be used.
www - web page
uk - country the site is registered in - 21What's an IP address?Globally unique address used to identify an individual device.
Ranges from 0.0.0.0 to 255.255.255.255 - 22What is an internet registrar?The organisation responsible for recording the allocations of public IP addresses.
- 23What's a protocol?A set of rules that allows communication.
- 24What's a domain name?User friendly reference that maps to an IP address.
- 25Who issues the IP addresses?Internet Registrar
- 26What are internet registries responsible for?Stores registered domain names
Maps domain names to IP addresses - 27What is the relationship between the IP address and the domain name?One to One
Domain name has a single IP address - 28Why do people prefer to use a Fully Qualified Domain Name rather than an IP address?Easier to remember a fully qualified domain name (IP addresses are less memorable).
Fully qualified domain name is easier to understand. - 29What does URI stand for and what does it do?Uniform Resource Identifier
Specifies how to access a resource on the Internet - 30What's the difference between a URL and a URN?URIs include URLs and URNs.
URL identifies a resource by its network location.
URN identifies it by name. - 31What's a DNS server?Domain name server
A server that translates fully qualified domain names into IP addresses. - 32Describe the stages of packet switching.When messages are broken down into smaller chunks called packets before they are sent out.
Each pocket is then transmitted that is routed from source to destination using routes.
Once all the packets arrive at the destination, they are recompiled into the original message. - 33What is the advantage of packet switching?Can easily get around broken bits of the network.
- 34What is the disadvantage of packet switching?The time it takes to put back the data package changes each time.
- 35What is the difference between circuit switching and packet switching?Circuit switching:
All packets are sent through the same switches.
No routing overhead.
All packets arrive in order they were sent.
Packets are not stored/queued for any length of time at switches.
Predictable delays.
Packet switching:
Packets do not necessarily travel through the same switches.
Can change route from packet to packet.
Packets can arrive out of order.
Queuing takes place at switches (packets can be stored for some time).
Involve unpredictable delays. - 36Give some roles of routers.Route packets according to destination IP address.
To manage congestion.
To choose an appropriate forwarding route.
To forward packets from one network to another. - 37What's a router?A device that receives packets from one computer
Uses the IP addresses that they contain to pass on these packets correctly formatted to another router/computer.
A device which uses IP addresses to route packets. - 38What are the tasks performed by the TCP?Sets packet size.
Splits the data into packets (dissembling messages + assembling packets).
Add TCP headers.
Add TCP trailer (error handling).
Check that transmission is successful.
Resend transmission if necessary.
Allocation of port numbers. - 39What are some of the well-known port numbers and their servers?20 - FTP server, file transfer data
21 - FTP server, file transfer control
80 and 8080 - web server
25 - SMTP server
110 - POP3 server
23 - Telnet server - 40What is a client port?Port that is temporarily assigned and only exists for duration of connection.
- 41A web server uses well-known port numbers to provide a service to client computers. Why must these port numbers be well known?Communication initiated by clients.
Clients must know which port number to connect to.
Particular port numbers are used to provide a particular service. - 42What is a socket?A combination of the IP address + port number.