Protocols
When two humans
converse, they may have to use the same language but they generally understand
each other without having to adhere to rigid rules of grammar or formal
language frameworks. Computers, on the other hand, have to have everything
explicitly defined and structured. If computers wish to communicate with one
another, they have to know in advance exactly how information is to be
exchanged and precisely what the format will be. Therefore, standard methods of
transmitting and processing various kinds of information are used and these
methods are called "protocols". Protocols are established by
international agreement and ensure that computers everywhere can talk to one
another. There are a variety of protocols for different kinds of information
and functions. This article will discuss some of the common protocols that the
average PC user is likely to encounter.
Types of protocols
HTTP (hyper text
transfer protocol)
DNS (Domain Name server)
ARP(Address Resolution Protocol)
RARP(Reverse Address Resolution Protocol )
ICMP(Internal Controal Message Protocol)
TELNET(Telecommunication network)
DHCP(Dynamic Host Configuration Protocol)
FTP(File transfer Protocol)
TFTP(Trivial File Transfer Protocol)
POP-3(Post office Protocol)
IMAP(Internal Message
Address Protocol)
SNMP(Simple network management Protocol)
SMTP(Simple Mail Transfer Protocol)
SSH(Server Shell)
Hypertext
Transfer Protocol
Web pages are constructed
according to a standard method called Hypertext Markup Language (HTML). An HTML
page is transmitted over the Web in a standard way and format known as
Hypertext Transfer Protocol (HTTP). This protocol uses TCP/IP to manage the Web
transmission.
A related protocol is
"Hypertext Transfer Protocol over Secure Socket Layer" (HTTPS), first
introduced by Netscape. It provides for the transmission in encrypted form to
provide security for sensitive data. A Web page using this protocol will
have https: at the front of its URL.
File Transfer
Protocol
File Transfer Protocol (FTP)
lives up to its name and provides a method for copying files over a network
from one computer to another. More generally, it provides for some simple file
management on the contents of a remote computer. It is an old protocol and is
used less than it was before the World Wide Web came along. Today, Its primary
use is uploading files to a Web site. It can also be used for downloading from
the Web but, more often than not, downloading is done via HTTP. Sites that have
a lot of downloading (software sites, for example) will often have an FTP
server to handle the traffic. If FTP is involved, the URL will have ftp: at
the front.
Mail Protocols
POP3 and SMTP
Email
requires its own set of protocols and there are a variety, both for sending and
for receiving mail. The most common protocol for sending mail is Simple Mail
Transfer Protocol (SMTP). When configuring email clients, an Internet address
for an SMTP server must be entered. The most common protocol used by PCs for
receiving mail is Post Office Protocol(POP). It is now in version 3 so it is
called POP3. Email clients require an address for a POP3 server before they can
read mail. The SMTP and POP3 servers may or may not be the same address. Both
SMTP and POP3 use TCP for managing the transmission and delivery of mail across
the Internet.
A
more powerful protocol for reading mail is Interactive Mail Access Protocol
(IMAP). This protocol allows for the reading of individual mailboxes at a
single account and is more common in business environments. IMAP also uses TCP
to manage the actual transmission of mail.
ICMP
A different type of protocol is Internet Control
Message Protocol (ICMP) . It defines a small number of messages used for
diagnostic and management purposes. It is also used by Ping and Traceroute.
DNS
Domain Name System - translates
network address (such as IP addresses) into terms understood by humans (such as Domain Names)
and vice-versa
DHCP
Dynamic Host Configuration Protocol - can automatically assign Internet
addresses to computers and users
FTP
File Transfer Protocol - a protocol that is used to transfer and
manipulate files on the Internet
HTTP
HyperText Transfer Protocol - An Internet-based protocol for sending and
receiving webpages
IMAP
Internet Message Access Protocol - A protocol for e-mail messages on the
Internet
IRC
Internet Relay Chat - a protocol
used for Internet chat and other communications
POP3
Post Office protocol Version 3 - a protocol used by e-mail clients to
retrieve messages from remote servers
SMTP
Simple Mail Transfer Protocol - A protocol for e-mail messages on the
Internet.
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