OPIC 3 Network Protocols and Security
Network Protocols PPP (Point-to-Point Protocol)
Protocol refers to the set of rules applicable for a Point-to-Point protocol is a data link layer protocol
ctwork. Many difterent types of network protocols and which encapsulates other network layer
andards are required to ensure that your computer (no transmission
protocols for
natteri which operating system and network card or
on synchronous and asynchronous
communication lines.
pplication, you are using) can communicate with another
The PPP is used with dial-up Internet connections
ompurer located on the next desk or half-way around the
including ISDN (Integrated Services Digital Nerwork). It is
rorld. alayered protocol, which is used for transmitting the IP data
The protocol defines standardised format for the data packets over usual telephone lines.
acket to be transmitted through the network.
There are three layers of PPP:
In a computer network, a protocol allows the setting up ) LCP (Link Control Protocol) LCP establishes the
favalid connection, communication and data transferring link between the source and destination.
erweeh ewo computing end points or computer system. (ii) NCP (Network Control Protocol) NCP controls
Some of the commonly used protocols are as follows: and transports the traffic.
(ii) IPCP (Internet Protocol Control Protocol) IPCP
HTTP (HyperText Transfer Protocol) permits the transformation of IP packets over the
HTTP is an application level protocol. It is used established PPP link.
widely. This protocol is used by the world wide HTTP
web. FTP (File Transfer Protocol)
iefines how messages are formatted and transmitted and
what actions web senvers and browsèrs should take in is
FTP designed
to transfer files from
one system to
esponse to various commands. another over a TCP-based nerwork, such as the Internet.
eg. when you enter a URL in your browser, this Using FTP, different people locating in different
geographical locations can cooperates and work on a
ictually sends a HTTP command to the web server
common project. FTP is designed to promote sharing of files
irectly, to fetch and transmit the requested web page. It is and to encourage the indirect use of remote computers.
eneric, stateless and object oriented protocol.
Using FTP, any type of file can be tranferred fro o n e
TCP/IP computer to another. Though for transferring files, we have
to specifiy whether the file is in ASCII format or in binary
(ransmission Control
format.
Protocol/internet Protocol)
TCP/IP is the communication protocol for the Remote Access Software
internet. It defines the rules, computers must follow to In remote access software, firstly we have to know about
communicate with each other over the Internet. The the term "remote access". Remote access refers to the ability
TCP/IP is a protocol used with E-mail transmission. Intact, to access a computer or a nerwork from a remore distance.
it is a set of protocol, i.e. TCP and IP. Remote access can be established via a line that runs between
The TCPIP is a protocol which is responsible for a computer and local area network.
the message
inding path for the destination. It also splits one daragram.
This type of line provide faster speeds but has the
nto several datagrams, if it does not fit in drawback of being more expensive. Another suitable method
Iherefore, these datagrams are sent through different for performing remote access by establishing a virtual private
towards the destination. The TCP makes
aternate paths nerwork, which is usually uses the Internet to connect
Sure that the datagram arrives at the destination correctly. remote site and users together.
P(Lnternet Protocol) used by the Internet for To establish a remote connection, both the local
machine to another,, The
ransterring messages from one
IP defines the machine and remote computer/server must have remote
DESsages are sent in the form of packets. data be delivered.
access sofrware. Remote access software dial indirecty to the
cker structures that encapsulate the
to
the network server.
are used to label
t also defines addressing methods that format.
datagram with source and destination
