Transcript Sem 1 V2 Chapter 2 OSI Model Presentation

Sem 1 V2
Chapter 2
OSI Model
All People Seem To Need Data Processing
OSI Model Application Layer
OSI Model Presentation Layer
OSI Model Session Layer
OSI Model Transport Layer
OSI Model Network Layer
OSI Model Data Link Layer
OSI Model Physical Layer
Although the OSI model is universally recognized, the historical and
technical open standard of the Internet is the TCP/IP reference model
and the TCP/IP protocol stack. TCP/IP makes data communication
between any two computers, anywhere in (or outside of) the world, at
nearly the speed of light ,and has historical importance - such as the
standards that allowed the telephone, electric, railroad, television, and
videotape industries to flourish.
file transport protocol (FTP)
hypertext transfer protocol (HTTP)
simple mail transport protocol (SMTP)
domain name service (DNS)
trivial file transport protocol (TFTP).
Similarities
*both have layers
* both have application layers, though
they include very different services
*both have comparable transport and
network layers
*packet-switched (not circuit-switched)
technology is assumed
*networking professionals need to
know both
Differences
*TCP/IP combines the presentation and
session layer issues into its application layer
*TCP/IP combines the OSI data link and
physical layers into one layer
*TCP/IP appears simpler because it has fewer
layers
*TCP/IP protocols are the standards around
which the Internet developed, so the TCP/IP
model gains credibility just because of its
protocols. In contrast, no networks are built
around specific OSI-related protocols, even
though everyone uses the OSI model to
guide their thinking.
Many networking professionals have different
opinions on which model to use. You should become
familiar with both. You will use the OSI model as the
microscope through which to analyze networks, but
you will also use the TCP/IP protocols throughout
the CNAP curriculum.
Remember that there is a difference between a model (i.e.
layers, interfaces, and protocol specifications) and an actual
protocol that is used in networking. You will use the OSI
model but the TCP/IP protocols.
You will focus on TCP as an OSI Layer 4 protocol,
IP as an OSI Layer 3 protocol, and Ethernet as a
Layer 2 and Layer 1 technology.
The END