3. What is a Protocol?
• A protocol is a collection of rules and
procedures for two computers to
exchange information
• Protocol also defines the format of
data that is being exchanged
4. What is a TCP/IP?
• TCP/IP stands for Transmission Control
Protocol / Internet Protocol, developed to
allow cooperating computers to share
resources / Information across a network
• A highly standardized protocol used widely
on the Internet
• TCP/IP protocols map to a four-layer
conceptual model known as the DARPA
(Defense Advanced Research Projects Agency) model
5. TCP/IP Layers:
Because TCP/IP was developed prior to the OSI 7layer mode, it does not have 7 layers but only 4
layers…
Application
Presentation
Application
Session
Transport
Host-to-Host/
Transport
Network
Internet
Data Link
Network Interface
Physical
OSI 7-layer
TCP/IP Protocol Suite
6. Continue…
The layers of TCP/IP protocol suite contain
relatively independent protocols that can be mixed
& matched depending on the need of the system.
Application
Presentation
Application
SMTP, PTP, HTTP, DNS,
SNMP, TELNET…
Session
Transport
Host-to-Host/
Transport
Network
Internet / Network
IP, ICMP, IGMP, RARP,
ARP
Network Interface
Ethernet, Token Ring,
Frame Relay, ATM
Data Link
Physical
OSI 7-layer
SCTP, TCP, UDP
TCP/IP Protocol Suite
7.
8. Network Interface Layer: (Physical & Data Link)
TCP/IP does not define any specific
protocol at this layer. It supports all the
standards & proprietary protocols.
– Ethernet
– Token Ring
– Frame Relay
– ATM (Asynchronous Transfer Mode)
9. Internet / Network Layer: (Network)
At this layer, TCP/IP supports the
Internetworking Protocols (IP) uses four
supporting protocols:
– ARP (Address Resolution Protocol)
– RARP (Reverse Address Resolution Protocol)
– ICMP (Internet Control Message Protocol)
– IGMP (Internet Group Message Protocol)
10. Transport / H-H Layer: (Transport)
At Transport / Host-to-Host layer, TCP/IP
is working with 3 Protocols that are
responsible for delivery of a message
from one device to another:
– UDP (User Datagram Protocol)
– TCP (Transmission Control Protocol)
– SCTP (Stream Control Transmission Protocol)
11. Application Layer: (Application, Presentation & Session)
This layer is equivalent to the upper three
layers of OSI model:
– HTTP (Hyper Text Transfer Protocol)
– FTP (File Transfer Protocol)
– SMTP (Simple Mail Transfer Protocol)
– DNS (Domain Name System)
– RIP (Routing Information Protocol)
– SNMP (Simple Network Management Protocol)
–…
13. HTTP?
• HTTP stands for Hyper Text Transfer
Protocol
• These are the rules governing the
conversation between a Web client and a
Web server
14. HTTP?
• HTTP
uses
services of TCP
the
• HTTP itself is a
stateless Protocol:
– Client and server establish
TCP connection
– Client requests content
– Server responds with
requested content
– Client and server close
connection (usually)
HTTP request
Web
Web
client
client
(browser)
(browser)
Web
Web
server
server
HTTP response
(content)
