2. OSI & TCP/IP MODELS
Application
Presentation
Session
SMTP FTP HTTP DNS POP3
Transport TCP UDP
Network
(Internet) IP
ICMP IGMP
RAPR ARP
Data link
Physical
Protocol defined by the underlying networks (host-to-network)
SCTP
3. TCP/IP MODEL
Application Layer
Application programs using the network
Transport Layer (TCP/UDP)
Management of end-to-end message transmission,
error detection and error correction
Network Layer (IP)
Handling of datagrams : routing and congestion
Data Link Layer
Management of cost effective and reliable data delivery,
access to physical networks
Physical Layer
Physical Media
4. TCP/IP
TCP/IP is a set of protocols developed to
allow cooperating computers to share
resources across a network
TCP stands for “Transmission Control
Protocol”
o IP stands for “Internet Protocol”
o They are Transport layer and Network layer
protocols respectively of the protocol suite
o The most well known network that adopted
TCP/IP is Internet – the biggest WAN in the
world
5. PROTOCOL
Protocol is a set of rules that govern data
communication.
The key element of protocol are :
SNYTAX
SEMANTICS
TIMING
6. APPLICATION LAYER PROTOCOLS
The application layer is responsible for
providing services to the user.
Typical protocols:
FTP – File Transfer Protocol
o For file transfer
o SMTP – Simple Mail Transfer Protocol
o For mail transfer
o HTTP – Hypertext Transfer Protocol
o For Web browsing
7. TRANSPORT LAYER PROTOCOL
TCP/IP is built on “connectionless” technology.
Typical protocols:
o TCP – Transmission Control Protocol
• Provide further the functions such as reordering and data
resend.
o UDP – User Datagram Service
• Use when the message to be sent fit exactly into a
datagram
8. NETWORK LAYER
Network layer protocols define the rules of how to
find the routes for a packet to the destination.
Typical protocols:
o IP – Internet Protocol
• Provide packet delivery
o ARP – Address Resolution Protocol
• Define the procedures of network address / MAC address
translation.
o ICMP – Internet Control Message Protocol
• Define the procedures of error message transfer
9. PHYSICAL AND DATA LINK LAYER
TCP/IP does not define any specific protocol .
It support all the standard and proprietary
protocols.A network in a TCP/IP internetwork
can be a local-area network or a wide-area
network.
