Network Hardware, Network Software, OSI Reference Model, TCP / IP model

1. Loyola College, Vettavalam. C - Programming Language By REX

3. Could be a group of people …. A network of friends.

4. Or, could be a set of computers communicating with each other.What is a network? Loyola College, Vettavalam.

6. Model

7. Size of Geographical Area coveredClassification of Networks Loyola College, Vettavalam.

9. Home Applications

10. Mobile Users

11. Social IssuesUses of Computer Networks Loyola College, Vettavalam.

12. . Some forms of e-commerce Loyola College, Vettavalam.

14. Person-to-person communication(Email, Instant Messaging etc, Phone)

15. Interactive entertainment(Remote operated or online Games)

16. Electronic commerceHome Network Applications Loyola College, Vettavalam.

17. Combinations of wireless networks and mobile computing. Mobile Network Users Loyola College, Vettavalam.

18. Client Server Model : A network with two clients and one server: Employees accessing company’s Information System Business Applications of Networks Loyola College, Vettavalam.

19. The client-server model involves requests and replies. Business Applications of Networks (2) Loyola College, Vettavalam.

20. In peer-to-peer system there are no fixed clients and servers. Peer-to-Peer Model of Communication Loyola College, Vettavalam.

22. Metropolitan Area Networks

23. Wide Area Networks

24. InternetworksNetwork Hardware Loyola College, Vettavalam.

26. Point-to-point linksBroadcast Networks Loyola College, Vettavalam.

27. Broadcast Networks (2) Classification of interconnected processors by scale. Loyola College, Vettavalam.

28. Two broadcast networks (a) Bus (b) Ring Local Area Networks Loyola College, Vettavalam.

29. A metropolitan area network based on cable TV. Metropolitan Area Networks Loyola College, Vettavalam.

30. Relation between hosts on LANs and the subnet. Wide Area Networks Loyola College, Vettavalam.

31. A stream of packets from sender to receiver. Wide Area Networks (2) Loyola College, Vettavalam.

33. Wireless LANs

34. Wireless WANsWireless Networks Loyola College, Vettavalam.

35. (a) Bluetooth configuration (b) Wireless LAN Wireless Networks (2) Loyola College, Vettavalam.

36. (a) Individual mobile computers (b) A flying LAN Wireless Networks (3) Loyola College, Vettavalam.

38. Entertainment (TV, DVD, VCR, camera, stereo, MP3)

39. Telecomm (telephone, cell phone, intercom, fax)

40. Appliances (microwave, fridge, clock, furnace, airco)

41. Telemetry (utility meter, burglar alarm, babycam).Home Network Categories Loyola College, Vettavalam.

43. Design Issues for the Layers

44. Connection-Oriented and Connectionless Services

45. Service Primitives

46. The Relationship of Services to ProtocolsNetwork Software Loyola College, Vettavalam.

47. OSI Model

48. Open Systems Interconnection (OSI) is a set of internationally recognized, non-proprietary standards for networking and for operating system involved in networking functions. Loyola College, Vettavalam.

49. 7 Layers 7. Application Layer Presentation Layer Session Layer Transport Layer Network Layer Data Link Layer Physical Layer All People Seem To Need Data Processing Loyola College, Vettavalam.

50. Tasks involved in sending letter Loyola College, Vettavalam.

54. For outgoing messages, it converts data into a generic format for network transmission; for incoming messages, it converts data from the generic network format to a format that the receiving application can understand

55. This layer is also responsible for certain protocol conversions, data encryption/decryption, or data compression/decompression

58. Applications on either end of the session are able to exchange data for the duration of the session

59. This layer is: Responsible for initiating, maintaining and terminating sessions

60. Responsible for security and access control to session information (via session participant identification)

63. Manages the flow of data between parties by segmenting long data streams into smaller data chunks (based on allowed “packet” size for a given transmission medium)

64. Reassembles chunks into their original sequence at the receiving end

67. Responsible for deciding how to route transmissions between computers

68. This layer also handles the decisions needed to get data from one point to the next point along a network path

70. the source host to the destination host.Loyola College, Vettavalam.

72. At the receiving end, this layer packages raw data from the physical layer into data frames for delivery to the Network layer

75. Converts electronic signals into bits for incoming messages

76. This layer manages the interface between the the computer and the network medium (coax, twisted pair, etc.)

77. This layer tells the driver software for the MAU (media attachment unit, ex. network interface cards (NICs, modems, etc.)) what needs to be sent across the medium

79. individual bits from one hop (node) to the next.Loyola College, Vettavalam.

80. A convenient aid for remembering the OSI layer names is to use the first letter of each word in the phrase: All People Seem To Need Data Processing Remember Loyola College, Vettavalam.

81. Layers, protocols, and interfaces. Network SoftwareProtocol Hierarchies Loyola College, Vettavalam.

82. Protocol Hierarchies (2) The philosopher-translator-secretary architecture. Loyola College, Vettavalam.

83. Example information flow supporting virtual communication in layer 5. Protocol Hierarchies (3) Loyola College, Vettavalam.

85. Error Control

86. Flow Control

87. Multiplexing

88. RoutingLoyola College, Vettavalam.

89. Six different types of service. Connection-Oriented and Connectionless Services Loyola College, Vettavalam.

90. Five service primitives for implementing a simple connection-oriented service. Service Primitives Loyola College, Vettavalam.

91. Packets sent in a simple client-server interaction on a connection-oriented network. Service Primitives (2) Loyola College, Vettavalam.

92. The relationship between a service and a protocol. Services to Protocols Relationship Loyola College, Vettavalam.

94. The TCP/IP Reference Model

95. A Comparison of OSI and TCP/IP

96. A Critique of the OSI Model and Protocols

97. A Critique of the TCP/IP Reference ModelReference Models Loyola College, Vettavalam.

98. Reference Models The OSI reference model. Loyola College, Vettavalam.

99. The TCP/IP reference model. Reference Models (2) Loyola College, Vettavalam.

100. Protocols and networks in the TCP/IP model initially. Reference Models (3) Loyola College, Vettavalam.

102. Interfaces

103. ProtocolsComparing OSI and TCP/IP Models Loyola College, Vettavalam.

105. Bad technology

106. Bad implementations

107. Bad politicsA Critique of the OSI Model and Protocols Loyola College, Vettavalam.

108. The apocalypse of the two elephants. Bad Timing Loyola College, Vettavalam.

110. Not a general model

111. Host-to-network “layer” not really a layer

112. No mention of physical and data link layers

113. Minor protocols deeply entrenched, hard to replaceLoyola College, Vettavalam.

114. The hybrid reference model to be used in this book. Hybrid Model Loyola College, Vettavalam.

116. Connection-Oriented Networks: X.25, Frame Relay, and ATM

117. Ethernet

118. Wireless LANs: 802:11Example Networks Loyola College, Vettavalam.

119. (a) Structure of the telephone system. (b)Baran’s proposed distributed switching system. The ARPANET(Advanced Research Project Agency Net) Loyola College, Vettavalam.

120. The original ARPANET design. The ARPANET (2) Loyola College, Vettavalam. Loyola College, Vettavalam.

121. The ARPANET (3) Growth of the ARPANET (a) December 1969. (b) July 1970. (c) March 1971. (d) April 1972. (e) September 1972. Loyola College, Vettavalam.

122. The NSFNET backbone in 1988. NSFNET Loyola College, Vettavalam.

124. News

125. Remote login

126. File transferInternet Usage Loyola College, Vettavalam.

127. Overview of the Internet. Architecture of the Internet Loyola College, Vettavalam.

128. A virtual circuit. ATM Virtual Circuits Loyola College, Vettavalam.

129. An ATM cell. ATM Virtual Circuits (2) Loyola College, Vettavalam.

130. The ATM reference model. The ATM Reference Model Loyola College, Vettavalam.

131. The ATM layers and sublayers and their functions. The ATM Reference Model (2) Loyola College, Vettavalam.

132. Architecture of the original Ethernet. Ethernet Loyola College, Vettavalam.

133. (a) Wireless networking with a base station. (b) Ad hoc networking. Wireless LANs Loyola College, Vettavalam.

134. The range of a single radio may not cover the entire system. Wireless LANs (2) Loyola College, Vettavalam.

135. IEEE 802 Standards The 802 working groups. The important ones are marked with *. The ones marked with  are hibernating. The one marked with † gave up. Loyola College, Vettavalam.

136. The principal metric prefixes. Metric Units Loyola College, Vettavalam.

137. 2.2 THE OSI MODEL Established in 1947, the International Standards Organization (ISO) is a multinational body dedicated to worldwide agreement on international standards. 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. Loyola College, Vettavalam.

139. Designer identified which networking functions had related uses and collected those functions into discrete groups that became the layers.

140. The OSI model allows complete interoperability between otherwise incompatible systems.

141. The Each layer uses the services of the layer immediately below it.Loyola College, Vettavalam.

142. Layered Architecture (cont’d) Figure 2.2Seven layers of the OSI model Loyola College, Vettavalam.

145. Network support layers : Layers 1, 2, 3

146. User support layer : Layer 5, 6, 7

147. It allows interoperability among unrelated software systems

148. Transport layer (Layer 4) : links the two subgroupsLoyola College, Vettavalam.

149. Peer-to-peer Processes (cont’d) Figure 2.3The interaction between layers in the OSI model Loyola College, Vettavalam.

151. 2.3 LAYERS IN THE OSI MODEL In this section we briefly describe the functions of each layer in the OSI model. Topics discussed in this section: Physical LayerData Link Layer Network Layer Transport Layer Session Layer Presentation Layer Application Layer Loyola College, Vettavalam.

153. The physical layer is responsible for movements of individual bits from one hop (node) to the next. Loyola College, Vettavalam.

155. Representation of bits

156. Data rate : transmission rate

157. Synchronization of bits

158. Line configuration

159. Physical topology

160. Transmission modeLoyola College, Vettavalam.

163. Framing

164. Physical addressing

165. Flow control

166. Error control

167. Access controlLoyola College, Vettavalam.

169. Network Layer Loyola College, Vettavalam.

171. Routing Loyola College, Vettavalam.

173. Transport Layer Loyola College, Vettavalam.

175. Segmentation and reassembly

176. Connection control

177. Flow control

178. Error controlLoyola College, Vettavalam.

180. Presentation Layer The presentation layer is responsible for translation, compression, and encryption Loyola College, Vettavalam.

181. TCP/IP Protocol Suite Figure 2.16TCP/IP and OSI model Loyola College, Vettavalam.

182. Physical Addresses Figure 2.18Relationship of layers and addresses in TCP/IP Loyola College, Vettavalam.

183. Logical Addresses (cont’d) Figure 2.20IP addresses The physical addresses will change from hop to hop, but the logical addresses usually remain the same. Loyola College, Vettavalam.

184. Port Addresses (cont’d) Figure 2.21Port addresses The physical addresses will change from hop to hop, but the logical and port addresses usually remain the same. Loyola College, Vettavalam.