:)

2. OSI Application Presentation Session Transport Network Data Link Physical Framing Error control Flow control Transmission/reception of frames MEDIA ACCESS sublayer LOGICAL LINK sublayer

4. Single communication channel that is shared by all the machines on the network Broadcast Networks 1 2 3 4 5 computer cable Packets Short messages sent by any machine are received by all others Fields Address General Rule: Smaller, geographically localized networks Quick Review…

5. Packets 1 2 3 4 5 ALL machines receive it, but one processes it Also possible to address a packet to ALL machines (special code in the address field) Mode of operation: Broadcasting Also possible to address a packet to a SUBSET of machines (group number code in the address field) Mode of operation: Multicasting Quick Review… 3

6. BROADCAST NETWORKS AND THEIR PROTOCOLS The Medium Access Sublayer deals with

18. Pure ALOHA

19. A Shared Medium  Collision Domain

36. IEEE 802.3: Minimum Frame Length In order to calculate the minimum frame length, we must first work out the propagation delay from one end of the cable to the other.

37. IEEE 802.3: Minimum Frame Length Propagation delay time: The round-trip propagation delay is, of course, twice this. Thus the round trip delay is With a data rate of each bit has duration Example #1: Cable = 400m, transm. speed = 10 Mbit/sec, propagation speed = 2*10**8 m/sec

39. Two nodes are communicating using CSMA/CD protocol. Speed transmission is 100 Mbits/sec and frame size is 1500 bytes. The propagation speed is 3*10**8 m/sec. Calculate the distance between the nodes such that the time to transmit the frame = time to recognize that the collision have occurred. EEE 802.3: Minimum Frame Length Example # 2

43. Ethernet Performance

62. Ethernet Bridges A bridge stores the hardware addresses observed from frames received by each interface and uses this information to learn which frames need to be forwarded by the bridge.

71. Repeater HUBs

72. Switches

73. Switches Repeater HUBs

75. Ethernet Switches and Multicast Traffic Multicast Traffic from F is delivered to all output interfaces (ports) which asks for it

76. Virtual LANs (VLANs) Cisco Systems

77. Cisco Systems

78. Virtual LANs (VLANs) Cisco Systems

79. Virtual LANs (VLANs) Cisco Systems

81. Where Does Wireless RF Live? ISM Band: Industrial, Scientific, Medical 902-928 MHz 2400-2483.5 MHz 5725-5850 MHz 802.11/802.11b 802.11a Bluetooth Cordless Phones Home RF Baby Monitors Microwave Ovens Old Wireless

85. The 802.11 Protocol Stack

86. Where does 802.11 live in the OSI? Telnet, FTP, Email, Web, etc. IP, ICMP, IPX TCP, UDP Logical Link Control - 802.2 (Interface to the upper layer protocols) MAC 802.3, 802.5, 802.11 LAN: 10BaseT, 10Base2, 10BaseFL WLAN: FHSS, DSSS, IR Application Presentation Session Transport Network Data Link Physical Wireless lives at Layers 1 & 2 only!

92. IEEE 802.5 and Token Ring

95. Bandwidth Scaling 1000 900 800 700 600 500 400 300 200 100 0 Mbps FE Ethernet Gigabit Ethernet (Switched) ATM OC-12 (Switched) ATM OC-3 (Switched) Fast Ethernet (Switched) FDDI (Switched) Token Ring (Switched) Ethernet (Switched) Switched LAN Type Cisco Systems