url and protocol
DESCRIPTION
Information TechnologyTRANSCRIPT
URL&
protocols
URL
A Uniform Resource Locator (URL) is a standard way developed to specify the location of a resource available electronically.
RFC 1738
URL
What are URLs? • URLs make it possible to direct both people
and software. • A URL is like your complete mailing
address: • In short, a URL is a very convenient way to
direct people to a file or other electronic resource.
• URLs assist your exploration of the Internet.
John Brown12 Stoke RoadStoke-on-Trent ST4 2DG
• Uniform Resource Locators (URLs) • http://news.bbc.co.uk/1/hi/education/5341426.stm
URL
General URL syntax
<scheme>:<scheme-dependent-information>
Scheme examples:– http (hyper text transfer protocol)– ftp (file transfer protocol) – news (news protocol)
URL
Scheme Dependent Information<scheme>:<scheme-dependent-information>
– The information is detailed with each scheme – Machine is used for making the file available
– "Path" provides the information
– Example (for HTTP):
http://www.7sport.net/7sport/index.htm
Machine Path
Scheme
URL
URL Example (explained)
http://www.7sport.net/7sport/index.htm
Machine Path
Scheme
• http is the scheme hyper text transfer protocol
• two slashes (//) separate the scheme from the machine/domain name
• www.7sport.net is the machine/domain name• single slash (/) separates the name from the path• Finally 7sport/index.htm is the path.
URLHTTP URL Example (explained)
http://www.w3schools.com/html/html_forms.asp
Machine/Domain Name Path
Scheme
• http is the scheme hyper text transfer protocol
• two slashes (//) separate the scheme from the machine/domain name
• www.w3schools.com is the machine/domain name• single slash (/) separates the name from the path• Finally html/html_forms.asp is the path.
URL
Troubleshooting URLsReasons for not being able to access URLs:– the remote machine refuses the
connection– the site is very busy (e.g. peak hours of
use)– you have misspelled the URL– the file was moved
Protocol
In computing, a protocol is a convention or standard that controls or enables the connection, communication, and data transfer between computing endpoints.
IP
Internet Protocol is a protocol which is responsible for addressing and packet routing between networks.
TCP
Transmission Control Protocol basically ensures that the packets get to their destination in the current sequence and without error.
FTP
File Transfer Protocol is a network protocol used to exchange and manipulate files over a TCP computer network, such as the Internet.
POP3
Post Office Protocol version 3 is an application-layer Internet standard protocol used by local e-mail clients to retrieve e-mail from a remote server over a TCP/IP connection.
SMTP
Simple Mail Transfer Protocol is an internet standard for e-mail transmission across internet protocol (IP) networks.
PPP
Point-to-Point Protocol, or PPP, is a data link protocol commonly used to establish a direct connection between two networking nodes. It can provide connection authentication, transmission encryption privacy, and compression.
Telnet
Telecommunication network is a network protocol used on the internet or local area networks. It provides access to a command-line interface on a remote machine.
HTTP
Hypertext Transfer Protocol is an application-level protocol for distributed, collaborative, hypermedia information systems. Its used for retrieving inter-linked resources led to the establishment of the world wide web (www).