Networking Protocol Stack

Transcription

1 Lecture Computer Communications & Networks 03 Networking Protocol Stack Dr. Muhammad Yousaf Assistant Professor, Faculty of Computing, Riphah International University, Islamabad

2 Networking Protocols Set of rules, that govern the communication between devices These rules dictate the actual implementation of communication tasks Usually implemented as software modules residing in OS, NIC, networking devices, etc. When data is ready to transmit, these software modules are executed These prepare the data for transmission 2

3 Protocols vs. Standards Protocol: Set of Rules Standard: Set of Agreed-Upon Rules

4 Protocol Models Initially each vendor developed its own protocols: Novel network protocols DECnet IBM s NetBIOS These were proprietary protocols A device using one vendor s protocol was not able to communicate with the device using other vendor s protocol There was a need to develop standard protocols: OSI Reference Model TCP / IP Protocol Suite muhammad.yousaf@riu.edu.pk 4

5 Proprietary Protocols vs. Standards 5

6 Protocol Architecture We have to perform many communication tasks Implementing all these tasks in a single module will make implementation complex Need to divide these complex tasks into simpler modules Individual modules should be independent enough from each other Each module is implemented as a separate layer in the architecture muhammad.yousaf@riu.edu.pk 6

7 Protocol Architecture 7

8 Layered Architecture 8

9 OSI Reference Model 9

10 OSI vs. ISO International Organization for Standardization (ISO) established in 1947 in Geneva, Switzerland Multinational body dedicated to worldwide agreement on international standards OSI is ISO standard that covers all aspects of network communications ISO = An organization OSI = network communications standard of ISO muhammad.yousaf@riu.edu.pk 10

11 OSI Reference Model Open Systems Interconnection (OSI) Developed by the ISO ISO/IEC :1994 Seven layers architecture Each layer performs a subset of required communication tasks Each layer provides services to the next layer Changes in one layer should not require changes in other layers muhammad.yousaf@riu.edu.pk 11

12 Seven Layers of OSI Model 12

13 OSI Reference Model: cont 13

14 Layers & their Headers Typical Total Size of all the Headers = 100 bytes Typical Total Length of Packet = 1500 bytes muhammad.yousaf@riu.edu.pk 14

15 Layers & Headers: cont 15

16 Why layered architecture? 16

17 Application Layer 17

18 Presentation Layer 18

19 Session Layer 19

20 Transport Layer 20

21 Network Layer 21

22 Data Link Layer 22

23 Physical Layer 23

24 Signal Transmission by Physical Layer Physical layer is responsible for movement of individual bits, in form of signals, from one node to the next. 24

25 Hop-to-Hop Delivery by Data Link Layer 25

26 Source-to-Destination Delivery by Network Layer 26

27 Process-to-Process Delivery by Transport Layer Also known as End-to-End Delivery 27

28 Summary of OSI Model 28

29 TCP / IP Protocol Suite muhammad.yousaf@riu.edu.pk 29

30 TCP / IP Protocol Suite Developed by IAB & IETF IAB = Internet Architecture Board IETF = Internet Engineering Task Force Global IETF Meetings, ISOC Islamabad Chapter Evolved from US DoD project ARPANET ARPANET = Advanced Research Projects Agency NETwork Protocol stack can be divided into 4 or 5 layers Most popular network protocol model Basis of the Internet muhammad.yousaf@riu.edu.pk 30

31 TCP/IP Development Timeline BSD = Berkley Software Distribution muhammad.yousaf@riu.edu.pk 31

32 TCP / IP Protocol Suite: cont HTTP = Hyper Text Transfer Protocol FTP = File Transfer Protocol SMTP = Simple Mail Transfer Protocol DNS = Domain Name System SNMP = Simple Network Management Protocol TCP = Transmission Control Protocol UDP = User Datagram Protocol IP = Internet Protocol ICMP = Internet Control Message Protocol IGMP = Internet Group Management Protocol ARP = Address Resolution Protocol RARP = Reverse ARP muhammad.yousaf@riu.edu.pk 32

33 Communication with TCP/IP 33

34 Communication with TCP/IP: cont... 34

35 Devices in Protocol Stack DNS=Domain Name System SSL=Secure Socket Layer NAT= Network Address Translation IPSec= IP Security ARP=Address Resolution Protocol L2TP= Layer 2 Tunneling Protocol PPTP= Point-to-Point Tunneling Protocol muhammad.yousaf@riu.edu.pk 35

36 Addressing at Different Layers of TCP/IP Stack :01:02:01:2C:4B 36

37 Data Naming Convention 37

38 OSI vs. TCP/IP Comparison 38

39 Other Protocol Types: IPX 39

40 Standards Organizations Famous organizations that define network/ communication standards are: IETF Internet Engineering Task Force IEEE Institute of Electrical and Electronic Engineering ETSI ITU ISO European Telecommunication Standard Institute International Telecommunication Union International Standardization Organization 40

41 Other Important Organizations Internet Corporation for Assigned Names and Numbers (ICANN) Asia Pacific Network Information Center (APNIC) Pakistan Telecommunications Authority (PTA) Ministry of IT & Telecomm (MoITT) 41

42 Assignment 02 Explore the ietf.org website and search out what are active areas of IETF. For this activity following links will be helpful for you. What to submit? Write a half page description of each of these areas Choose one of these areas as your favorite area and write a half page note explaining why you choose this area Deadline: Wednesday, October 21, 2015 muhammad.yousaf@riu.edu.pk 42

43 Questions??? 43