1. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Internetworking
Chapter 2
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

2. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Technology
Describe Network communications using layered models
Compare and contrast key characteristics of LAN environments
Describe the components of network devices
Evaluate rules for packet control
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

3. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Agenda
Internetworking Basics
Internetworking Model
The OSI Reference Model
Ethernet Networking
Wireless Networking
Data Encapsulation
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

4. Possible causes of LAN traffic congestion are
Too many hosts in a broadcast domain
Broadcast storms
Multicasting
Low bandwidth
Adding hubs for connectivity to the network
A large amount of ARP or IPX traffic (IPX is a Novell
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

5. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Network Segmentation
Collision domain
Broadcast domain
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

6. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

7. Two advantages of using routers in your network are
They don’t forward broadcasts by default.
They can filter the network based on layer 3 (Network layer) information (i.e., IP address).
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

8. Four router functions in your network can be listed as
Packet switching
Packet filtering
Internetwork communication
Path selection
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

9. Internetworking Model
The Layered Approach
Advantages of Reference Models
It divides the network communication process into smaller and simpler components, thus aiding component development, design, and troubleshooting.
It allows multiple-vendor development through standardization of network components.
It encourages industry standardization by defining what functions occur at each layer of the model.
It allows various types of network hardware and software to communicate.
It prevents changes in one layer from affecting other layers, so it does not hamper development.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

10. The OSI Reference Model
The upper layers
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

11. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The lower layers
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

12. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Layer functions
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

13. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Application Layer
The Application layer of the OSI model marks the spot where users actually communicate to the computer.
Sample ->
World Wide Web (WWW)
gateways
Electronic data interchange (EDI)
Special interest bulletin boards
Internet navigation utilities
Financial transaction services13
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

14. The Presentation Layer
It presents data to the Application layer and is responsible for data translation and code formatting.
This layer is essentially a translator and provides coding and conversion functions. A successful data-transfer technique is to adapt the data into a standard format before transmission.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

15. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The Session Layer
The Session layer is responsible for setting up, managing, and then tearing down sessions between Presentation layer entities.
This layer also provides dialogue control between devices, or nodes. It coordinates communication between systems, and serves to organize their communication by offering three different modes: simplex, half duplex, and full duplex.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

16. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The Transport Layer
The Transport layer segments and reassembles data into a data stream.
Services located in the Transport layer both segment and reassemble data from upper-layer applications and unite it onto the same data stream.
They provide end-to-end data transport services and can establish a logical connection between the sending host and destination host on an internetwork.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

17. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The Transport layer is responsible for providing mechanisms for multiplexing upper-layer applications, establishing sessions, and tearing down virtual circuits.
The Transport layer can be connectionless or connection-oriented.
Some of you are probably familiar with TCP and UDP already.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

18. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Flow Control
Data integrity is ensured at the Transport layer by maintaining flow control and by allowing users to request reliable data transport between systems.
The segments delivered are acknowledged back to the sender upon their reception.
Any segments not acknowledged are retransmitted.
Segments are sequenced back into their proper order upon arrival at their destination.
A manageable data flow is maintained in order to avoid congestion, overloading, and data loss.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

19. Connection-Oriented Communication
a call setup, or a three way handshake
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20. Transmitting segments with flow control
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21. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Windowing
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22. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Acknowledgments
It guarantees that the data won’t be duplicated or lost.
This is achieved through something called positive acknowledgment with retransmission a technique that requires a receiving machine to communicate with the transmitting source by sending an acknowledgment message back to the sender when it receives data.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

23. Transport layer reliable delivery
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24. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The Network Layer
The Network layer (also called layer 3) manages device addressing, tracks the location of devices on the network, and determines the best way to move data, which means that the Network layer must transport traffic between devices that aren’t locally attached.
Two types of packets are used at the Network layer:
Data packets : routed protocol
Route update packets : routing protocol
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

25. Routing table used in a router
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

26. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Here are some points about routers that you should really commit to memory:
Routers, by default, will not forward any broadcast or multicast packets.
Routers use the logical address in a Network layer header to determine the next hop router to forward the packet to.
Routers can use access lists, created by an administrator, to control security on the types of packets that are allowed to enter or exit an interface.
Routers can provide layer 2 bridging functions if needed and can simultaneously route through the same interface.
Layer 3 devices (routers in this case) provide connections between virtual LANs (VLANs).
Routers can provide quality of service (QoS) for specific types of network traffic.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

27. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The Data Link Layer
The Data Link layer provides the physical transmission of the data and handles error notification, network topology, and flow control.
The Data Link layer formats the message into pieces, each called a data frame, and adds a customized header containing the hardware destination and source address.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

28. Data Link layer with the Ethernet and IEEE specifications.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

29. The IEEE Ethernet Data Link layer has two sublayers:
Media Access Control (MAC) Defines how packets are placed on the media. Contention media access is “first come/first served” access where everyone shares the same bandwidth—hence the name. Physical addressing is defined here,
Logical Link Control (LLC) Responsible for identifying Network layer protocols and then encapsulating them.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

30. Switches and Bridges at the Data Link Layer
Layer 2 switching is considered hardware-based bridging because it uses specialized hardware called an application-specific integrated circuit (ASIC).
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

31. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The Physical Layer
we find that the Physical layer does two things: It sends bits and receives bits. Bits come only in values of 1 or 0—a Morse code with numerical values.
The Physical layer specifies the electrical, mechanical, procedural, and functional requirements for activating, maintaining, and deactivating a physical link between end systems.
This layer is also where you identify the interface between the data terminal equipment (DTE) and the data communication equipment (DCE).
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

32. Hubs at the Physical Layer
A hub is really a multiple-port repeater. A repeater receives a digital signal and reamplifies or regenerates that signal, and then forwards the digital signal out all active ports without looking at any data.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

33. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Ethernet Networking
Lecture 2-2
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

34. The success of Ethernet is due to the following factors:
Simplicity and ease of maintenance
Ability to incorporate new technologies
Reliability
Low cost of installation and upgrade
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

35. 802.3 Ethernet in Relation to The OSI Model
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

36. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
IEEE 802.x Standards
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

37. Ethernet Technologies Mapped to the OSI model
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

38. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Ethernet Addressing
We get into how Ethernet addressing works. It uses the Media Access Control (MAC) address burned into each and every Ethernet Network Interface Card (NIC).
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

39. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
MAC Address Format
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

40. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Generic Frame Format
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

41. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
IEEE 802.3
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

42. Ethernet II Frame Format
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43. Ethernet II and IEEE 802.3 Frame Format
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44. Media Access Control (MAC)
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45. MAC Rules and Collision Detection/Backoff
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46. MAC Rules and Collision Detection/Backoff
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

47. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Ethernet Timing
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

48. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Interframe Spacing
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

49. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Backoff
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

50. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Error Handling
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51. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Types of Collisions
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

52. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The effects of having a CSMA/CD network sustaining heavy collisions include
Delay
Low throughput
Congestion
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

53. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Ethernet Errors
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

54. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Ethernet Errors
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

55. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
FCS Errors
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

56. Parameters for 10 Mbps Ethernet Operation
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

57. Manchester Encoding Examples
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

58. Parameters for 100-Mbps Ethernet Operation
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

59. MLT-3 Encoding Example (100Base-TX)
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

60. NRZI Encoding Examples (100Base-FX)
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

61. Parameters for Gigabit Ethernet Operation
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

62. Actual 1000Base-T Signal Transmission
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

63. Gigabit Ethernet Layers
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

64. Gigabit Ethernet Media Comparison
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

65. Parameters for 10-Gbps Ethernet Operation
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

66. 10GBASE LX-4 Signal Multiplexing
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

67. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Wireless Networking
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

68. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Benefits of WLANs
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

69. Evolution of Wireless LANs
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

70. Unlicensed Frequency Bands
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

71. Wireless Technologies
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

72. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Distance Versus Speed
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

73. Wireless Technologies
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

74. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
In-Building WLANs
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

75. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
The IEEE 802 Standards
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

76. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
IEEE Protocols
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

77. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
IEEE Standards
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

78. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Data Encapsulation
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

79. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Data Encapsulation
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

80. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

81. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.

82. Computer Network by P.It-arun Computer Engineering Dept, RMUTT.
Summary
OSI model—the seven-layer model used to help application developers design applications that can run on any type of system or network. Each layer has its special jobs and select responsibilities within the model to ensure that solid, effective communications do, in fact, occur.
Remember that hubs are Physical layer devices and repeat the digital signal to all segments except the one it was received from.
Switches segment the network using hardware addresses and break up collision domains.
Routers break up broadcast domains (and collision domains) and use logical addressing to send packets through an internetwork.
Computer Network by P.It-arun Computer Engineering Dept, RMUTT.