Download - Computer Network - Introduction to Networks
Parul Institute of Engineering & Technology
Subject Code : 150702
Name Of Subject : COMPUTER NETWORK
Name of Unit : INTRODUCTION TO NETWORKS
Topic : OSI MODEL , TCP/IP MODEL AND COMPARISON
OF OSI & TCP/IP MODEL
Name of Student :Agrawal Swapnil J.
• OSI MODEL
• THE OSI MODEL• DIFFERENT LAYERS OF OSI REFERENCE MODEL• EXCHANGE OG INFORMATION IN OSI MODEL• OSI FEATURES
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
CONTENTS
• TCP/IP MODEL• INTRODUCTION TO TCP/IP• LAYERS IN TCP/IP• TCP/IP STACK• TCP/IP ENCAPSULATION• TCP/IP PROTOCOL
• COMPARISON OF OSI & TCP/IP MODEL
CONTENTS
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Established in 1947, the International Standards Organization (ISO) is a multinational body dedicated to worldwide agreement on international standards.
Almost three-fourths of countries in the world are represented in the ISO. An ISO standard that covers all aspects of network communications is the Open Systems Interconnection (OSI) model. It was first introduced in the late 1970s.
THE OSI MODEL
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
The OSI model
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
OSI LayersOSI LayersOSI Model
Data unit Layer Function
Hostlayers
Data
7. ApplicationNetwork process to application
6. PresentationData representation, encryption and decryption
5. Session Innermost communication
Segments 4. TransportEnd-to-end connections and reliability, Flow control
Medialayers
Packet 3. NetworkPath determination and logical addressing
Frame 2. Data Link Physical addressing
Bit 1. PhysicalMedia, signal and binary transmission
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
OSI LayersOSI Layers
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Layer1: Physical LayerLayer1: Physical Layer
• The Physical Layer defines the electrical and physical specifications for devices. In particular, it defines the relationship between a device and a physical medium.
• This includes the layout of pin, voltages, cable specification, hubs, repeaters, network adapters, host bus adapters, and more.
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
• The Data Link Layer provides the functional and procedural means to transfer data between network entities and to detect and possibly correct errors that may occur in the Physical Layer.
• Originally, this layer was intended for point-to-point and point-to-multipoint media, characteristic of wide area media in the telephone system.
• The data link layer is divided into two sub-layers by IEEE.
Layer 2: Data Link LayerLayer 2: Data Link Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
• The Network Layer performs–network routing functions, –perform fragmentation and reassembly, – report delivery errors.
• Routers operate at this layer—sending data throughout the extended network and making the Internet possible.
Layer 3: Network LayerLayer 3: Network Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
• The Network Layer provides the functional and procedural means of transferring variable length data sequences from a source to a destination via one or more networks, while maintaining the quality of service requested by the Transport Layer.
Layer 3: Network LayerLayer 3: Network Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
• The Transport Layer provides transparent transfer of data between end users, providing reliable data transfer services to the upper layers.
• The Transport Layer controls the reliability of a given link through flow control, segmentation/documentation, and error control.
Layer 4: Transport LayerLayer 4: Transport Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
• The Session Layer controls the dialogues (connections) between computers.
• It establishes, manages and terminates the connections between the local and remote application.
• It provides for full-duplex, half-duplex, or simplex operation, and establishes check pointing, adjournment, termination, and restart procedures.
Layer 5: Session LayerLayer 5: Session Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
• This layer provides independence from differences in data representation (e.g., encryption) by translating from application to network format, and vice versa.
• This layer formats and encrypts data to be sent across a network, providing freedom from compatibility problems.
• It is sometimes called the syntax layer.
Layer 6: Presentation LayerLayer 6: Presentation Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
• The application layer is the OSI layer closest to the end user, which means that both the OSI application layer and the user interact directly with the software application.
• Application layer functions typically include:– identifying communication partners, –determining resource availability,–synchronizing communication.
Layer 7: Application LayerLayer 7: Application Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
An exchange using the OSI model
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Summary of OSI Layers
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
OSI FeatureOSI Feature
Open system standards over the world
Rigorously defined structured, hierarchical network model
Complete description of the function
Provide standard test procedures
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Introduction TCP/IPIntroduction TCP/IP
• The Internet Protocol Suite (commonly known as TCP/IP) is the set of communications protocols used for the Internet and other similar networks.
• It is named from two of the most important protocols in it: – the Transmission Control Protocol (TCP) and– the Internet Protocol (IP), which were the
first two networking protocols defined in this standard.
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Layers in the TCP/IP Protocol Suite
Original Layers (Practically)
Layers According to Book(Theoretically)
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
The Upper Layers
OSI TCP / IP
Application (Layer7)
ApplicationPresentation (Layer6)
Session (Layer 5)
SessionSession
PresentationPresentation
ApplicationApplicationSub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
The Session Layer
The Session layer permits two parties to hold ongoing communications called a session across a network.
Not found in TCP/IP model In TCP/IP , its characteristics are provided by the TCP
protocol. (Transport Layer)
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
The Presentation Layer The Presentation Layer handles data format
information for networked communications. This is done by converting data into a generic format that could be understood by both sides.
Not found in TCP/IP model In TCP/IP, this function is provided by the Application
Layer.
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
The Application Layer
The Application Layer is the top layer of the reference model. It provides a set of interfaces for applications to obtain access to networked services as well as access to the kinds of network services that support applications directly.
OSI - FTAM,VT,MHS,DS,CMIPTCP/IP- FTP,SMTP,TELNET,DNS,SNMP
Although the notion of an application process is common to both, their approaches to constructing application entities is different.
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
TCP/IP Transport Layer
Defines two standard transport protocols: TCP and UDP
TCP implements a reliable data-stream protocol– connection oriented
UDP implements an unreliable data-stream – connectionless
TCP provides reliable data transmission
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
TCP/IP StackTCP/IP Stack
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
TCP/IP EncapsulationTCP/IP Encapsulation
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
TCP/IP Some ProtocolTCP/IP Some ProtocolLayer Protocol
Application
DNS, TFTP, TLS/SSL, FTP, Gopher, HTTP, IMAP, IRC, NNTP, POP3, SIP, SMTP, SMPP, SNMP, SSH, Telnet, Echo, RTP, PNRP, rlogin, ENRP
Routing protocols like BGP and RIP which run over TCP/UDP, may also be considered part of the Internet Layer.
Transport TCP, UDP, DCCP, SCTP, IL, RUDP, RSVP
Internet
IP (IPv4, IPv6), ICMP, IGMP, and ICMPv6
OSPF for IPv4 was initially considered IP layer protocol since it runs per IP-subnet, but has been placed on the Link since RFC 2740.
Link ARP, RARP, OSPF (IPv4/IPv6), IS-IS, NDP
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Comparison of Both LayersComparison of Both LayersOSI TCP/IP
Application LayerApplication Layer
TELNET, FTP, SMTP, POP3, SNMP, NNTP, DNS,NIS, NFS,
HTTP, ...
Presentation Layer
Session Layer
Transport Layer Transport Layer TCP , UDP , ...
Network Layer Internet Layer IP , ICMP, ARP, RARP, ...
Data Link LayerLink Layer
FDDI, Ethernet, ISDN, X.25,...Physical Layer
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Comparison of TCP/IP and OSI model
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Comparing Transport for both Models
• The features of UDP and TCP defined at TCP/IP Transport Layer correspond to many of the requirements of the OSI Transport Layer.
• There is a bit of bleed over for requirements in the session layer of OSI since sequence numbers, and port values can help to allow the Operating System to keep track of sessions, but most of the TCP and UDP functions and specifications map to the OSI Transport Layer.
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
Comparing Transport for both Models
• The TCP/IP and OSI architecture models both employ all connection and connectionless models at transport layer. However, the internet architecture refers to the two models in TCP/IP as simply “connections” and datagram's.
• But the OSI reference model, with its penchant for “precise” terminology, uses the terms connection-mode and connection-oriented for the connection model and the term connectionless-mode for the connectionless model.
Sub:-COMPUTER NETWORK Topic:-OSI,TCP/IP MODEL & COMPARISON
THANK YOU
REFERENCES
Books:-1.COMPUTER NETWORKS
Fourth Edition by Andrew S. TanenbaumWeb Resources:-
1.Google2.Wikipedia
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