Presentation is loading. Please wait.

Presentation is loading. Please wait.

Introduction to TCP/IP and OSI model 1/12/20141Mr. Naresh Sharma,

Similar presentations

Presentation on theme: "Introduction to TCP/IP and OSI model 1/12/20141Mr. Naresh Sharma,"— Presentation transcript:

1 Introduction to TCP/IP and OSI model 1/12/20141Mr. Naresh Sharma,

2 More OSI Info Who made up the OSI? It was created by the International Organization for Standardization (ISO) 1/12/20142Mr. Naresh Sharma,

3 The Open System Interconnection Model (OSI) The International Standards Organization (ISO) has developed a universal architecture for computer communications. This standard, Known as the open Systems Interconnection model, or OSI model. The purpose of OSI is to permit communications among devices made by manufacturers. 1/12/20143 Mr. Naresh Sharma,

4 OSI Layers OSI has seven layers. Each layer represents a particular function. It could be, each function is preformed by a separate piece of hardware or software. Sometimes, a single program may performed the functions of several layers. All layers are necessary for communications to occur. 1/12/20144Mr. Naresh Sharma,

5 OSI Layers The ISO-OSI model chooses to divided the function of computer communications into seven layers, though more or fewer could have been chosen. 1/12/20145Mr. Naresh Sharma,

6 What is the OSI Reference Model? It is a conceptual framework specifying the network functions that occur at each layer It is a way of picturing how information travels through networks. 1/12/20146Mr. Naresh Sharma,

7 OSI Reference Model (standard) Any application process should be able to communicate freely with any any application process in any other computer that supports the same standards… The OSI Reference Model shows how this takes place. 1/12/20147Mr. Naresh Sharma,

8 OSI Reference Model The OSI reference model describes how data makes its way from application programs through a network medium to another application located on another computer on a network 1/12/20148Mr. Naresh Sharma,

9 To accomplish this task data must travel from the application layer to the physical layer on one computer across the network media and from the physical layer to the application layer of another computer Computer A Computer B 1/12/20149Mr. Naresh Sharma,

10 OSI Reference Model Layers The Application Layer provides services to application processes (such as electronic mail, file transfer, and terminal emulation) that are outside of the OSI model. The application layer identifies and establishes the availability of intended communication partners (and the resources required to connect with them), synchronizes cooperating applications, and establishes agreement on procedures for error recovery and control of data integrity. 1/12/201410Mr. Naresh Sharma,

11 OSI Reference Model The Presentation Layer ensures that information sent by the application layer will be readable by the application layer of the receiving system. The presentation layer is also concerned with the data structures used by programs and therefore negotiates data transfer syntax for the application layer. 1/12/201411Mr. Naresh Sharma,

12 OSI Reference Model The Session Layer establishes, manages, and terminates sessions between applications and manages data exchange between presentation layer entities (Ensures Interhost communication) 1/12/201412Mr. Naresh Sharma,

13 OSI Reference Model The Transport Layer is responsible for reliable network communication between end nodes. The transport layer provides mechanisms for the establishment, maintenance, and termination of virtual circuits, transport fault detection and recover, and information flow control. 1/12/201413Mr. Naresh Sharma,

14 OSI Reference Model The Network Layer provides connectivity and path selection between two end systems. The network layer is the layer at which routing occurs. 1/12/201414Mr. Naresh Sharma,

15 OSI Reference Model The Data Link Layer provides reliable transit of data across a physical link. The data link layer is concerned with – physical addressing, – network topology, – line discipline, – error notification, – ordered delivery of frames, – flow control. 1/12/201415Mr. Naresh Sharma,

16 OSI Reference Model The physical layer defines the electrical, mechanical, procedural, and functional specifications for activating, maintaining, and deactivating the physical link between end systems 1/12/201416Mr. Naresh Sharma,

17 OSI Reference Model Host Layers: } Media Layers: } Control physical delivery of messages over a network Provide accurate data delivery between computers 1/12/201417Mr. Naresh Sharma,

18 As data moves down through the layers of the OSI model, headers are added. Computer A 1/12/201418Mr. Naresh Sharma,

19 Computer B As data moves up through the layers of the OSI model, headers are removed. 1/12/201419Mr. Naresh Sharma,

20 OSI Reference Model There are other models by different vendors Most vendors use the OSI Model OSI is conceptual other than tangible Used to educate how networks function at each layer 1/12/201420Mr. Naresh Sharma,

21 What does the OSI Model do? It reduces complexity (from one big problem to 7 small ones) It standardizes interfaces It facilitates modular engineering It assures interoperable technology Accelerates evolution Simplifies teaching & learning 1/12/201421Mr. Naresh Sharma,

22 Review Time! Divide into two groups Play Jeopardy Bonus answer is the layer number 1/12/201422Mr. Naresh Sharma,

23 OSI Layers The Lowest layer, Known as physical Layer or Layer 1, – is responsible for transmission of bits. – Is always implemented by using hardware. – Is encompasses the mechanical, electrical, and functional interface. – Is the interface to the outside world – using electronic signals as specified by interface standards. 1/12/201423Mr. Naresh Sharma,

24 OSI Layers The Data Link Layer, Or Layer 2, – is responsible for ensuring error-free, – reliable transmission of data. – Scrutinizes the bits received to determine if errors occurred during transmission. – Is able to request retransmission or correction of any errors using protocols. 1/12/201424Mr. Naresh Sharma,

25 OSI Layers The Network Layer, or Layer 3, – is responsible for setting up the appropriate routing of messages throughout a network – is concerned with he types of switching networks used to route the data Note: Physical, Data Link, and Network layers are usually referred to as the lower layers 1/12/201425Mr. Naresh Sharma,

26 OSI Layers The Transport Layer, or Layer 4, – is responsible for isolating the function of the lower layers from the higher layers – is responsible for monitoring the quality of the communication channel – is responsible for selecting the most cost efficient communication service. – accepts messages from higher layers, and breaks them down into messages that can be accepted by the lower layers 1/12/201426Mr. Naresh Sharma,

27 OSI Layers The Session Layer, or Layer 5, – is responsible for terminating the connection – requests a logical connection be established based on the end users request – handles any necessary log-on and password procedures. 1/12/201427Mr. Naresh Sharma,

28 OSI Layers The Presentation Layer, or Layer 6, – provides format and code conversion services – handles any necessary conversion different character codes; example ASCII-to- EBCDIC 1/12/201428Mr. Naresh Sharma,

29 OSI Layers The Application Layer or Layer 7, – provides access to the network for the end user – determines the users capabilities on the network – some Application Layer software, permit remote terminal to only access a host computer; other Application Layer software might also permit file transfers. 1/12/201429Mr. Naresh Sharma,

30 The TCP/IP Protocol Suite The TCP/IP Suite – is a collection of protocols originally designed for use on an network connecting U.S. government agencies with universities performing research – specifies protocols at various levels of the OSI model and covers a wide variety of tasks likely to be performed on an open network 1/12/201430Mr. Naresh Sharma,

31 Comparison of ISO-OSI Model and the DOD (TCP/IP) Model Application Presentation Session TransportHost-to-Host NetworkInternet Data Link Network Access Physical Source: 1/12/201431Mr. Naresh Sharma,

32 Layers How network hardware and software work together in layered fashion to make communication possible Each layer covers different network activities, equipment and protocols. 1/12/201432Mr. Naresh Sharma,

33 1/12/201433Mr. Naresh Sharma,

34 1/12/201434Mr. Naresh Sharma,

35 OSI Open Systems Interconnection developed by the International Organization for Standardization (ISO) has seven layers is a theoretical system delivered too late! TCP/IP is the de facto standard 1/12/201435Mr. Naresh Sharma,

36 OSI Layers 1/12/201436Mr. Naresh Sharma,

37 ApplicationProvides access to the OSI environment for users and also provides distributed information service PresentationProvides independence to the application process from difference in data representation (syntax) SessionProvides the control structure for communication between application; establishes, manages ___ terminates connection (session) between cooperating applications. TransportProvides reliable, transparent transfer data between end points; provides end-to-end error recovery and flow control. networkProvides upper layer with independence from the data transmission and switching technologies used to connect systems; responsible for establishing, maintaining, and terminating connections. Data LinkProvides for the reliable transfer of information across the physical link; sends blocks of data (frames) with the necessary synchronization, error control,and flow control PhysicalConcerned with transmission of unstructured bit stream over physical medium; deals with the mechanical, electrical, functional and procedural characteristics to access the physical 1/12/201437Mr. Naresh Sharma,

38 Physical Concerned with transmission of unstructured bit stream over physical medium Deals with the mechanical, electrical, functional and procedural characteristics to access the physical medium 0,1 – Volt, duration, transmission characteristic directions, connectors pins 1/12/201438Mr. Naresh Sharma,

39 Data Link Provides for the reliable transfer of information across the physical link Sends blocks of data (frames) with the necessary synchronization, error control and flow control Frame, acknowledgment from lost, duplicate Piggy backing 1/12/201439Mr. Naresh Sharma,

40 Network Provides upper layer with independence from the data transmission and switching technologies used to connect systems Responsible for establishing, maintaining, and terminating connections. Operations of subnet, Packet size Routing, congestion control network Addressing Accounting Broadcast networks 1/12/201440Mr. Naresh Sharma,

41 Transport Provides reliable, transparent transfer of data between end points Provides end-to-end error recovery and flow control. Addressing port, connection management Distinctive network connection, multiplexing 1/12/201441Mr. Naresh Sharma,

42 Session Provides the control structure for communication between applications Establishes, manages and terminates connections (sessions) between cooperating applications. Dialog management Token Management synchronization 1/12/201442Mr. Naresh Sharma,

43 Presentation Provides independence to the application processes from difference in data representation (syntax) ASCII, Unicode 1/12/201443Mr. Naresh Sharma,

44 Application Layer Provides access to the OSI environment for users Provides distributed information services. Web browsing (http) (smtp) 1/12/201444Mr. Naresh Sharma,

45 Need For Protocol Architecture data exchange can involve complex procedures, cf. file transfer example better if task broken into subtasks implemented separately in layers in stack – each layer provides functions needed to perform comms for layers above – using functions provided by layers below peer layers communicate with a protocol 1/12/201445Mr. Naresh Sharma,

46 Key Elements of a Protocol syntax - data format semantics - control info & error handling timing - speed matching & sequencing 1/12/201446Mr. Naresh Sharma,

47 TCP/IP Protocol Architecture developed by US Defense Advanced Research Project Agency (DARPA) for ARPANET packet switched network used by the global Internet protocol suite comprises a large collection of standardized protocols 1/12/201447Mr. Naresh Sharma,

48 Simplified Network Architecture 1/12/201448Mr. Naresh Sharma,

49 TCP/IP Layers no official model but a working one – Application layer – Host-to-host, or transport layer – Internet layer – Network access layer – Physical layer 1/12/201449Mr. Naresh Sharma,

50 Physical Layer concerned with physical interface between computer and network concerned with issues like: – characteristics of transmission medium – signal levels – data rates – other related matters 1/12/201450Mr. Naresh Sharma,

51 Network Access Layer exchange of data between an end system and attached network concerned with issues like : – destination address provision – invoking specific services like priority – access to & routing data across a network link between two attached systems allows layers above to ignore link specifics 1/12/201451Mr. Naresh Sharma,

52 Internet Layer (IP) routing functions across multiple networks for systems attached to different networks using IP protocol implemented in end systems and routers routers connect two networks and relays data between them 1/12/201452Mr. Naresh Sharma,

53 Transport Layer (TCP) common layer shared by all applications provides reliable delivery of data in same order as sent commonly uses TCP 1/12/201453Mr. Naresh Sharma,

54 Application Layer provide support for user applications need a separate module for each type of application 1/12/201454Mr. Naresh Sharma,

55 OSI v TCP/IP 1/12/201455Mr. Naresh Sharma,

56 1/12/201456Mr. Naresh Sharma,

57 TCP/IP Applications have a number of standard TCP/IP applications such as – Simple Mail Transfer Protocol (SMTP) – File Transfer Protocol (FTP) – Telnet 1/12/201457Mr. Naresh Sharma,

58 Some TCP/IP Protocols 1/12/201458Mr. Naresh Sharma,

Download ppt "Introduction to TCP/IP and OSI model 1/12/20141Mr. Naresh Sharma,"

Similar presentations

Ads by Google