27. MAC Sub-layer Data link layer 802.3 CSMA-CD 802.5 Token Ring 802.2 Logical link control Physical layer MAC LLC 802.11 Wireless LAN Network layer Network layer Physical layer OSI IEEE 802 Various physical layers Other LANs
53. IEEE 802.3 Physical Layer IEEE 802.3 10 Mbps medium alternatives Thick Coax: Stiff, hard to work with T connectors flaky Hubs & Switches! (a) transceivers (b) Point-to-point link Star Bus Bus Topology 2 km 100 m 2 00 m 5 00 m Max. Segment Length Optical f iber T wisted pair Thin coax Thick coax Medium 10base FX 10base T 10base 2 10base 5
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56. Ethernet Hubs & Switches Twisted Pair Cheap Easy to work with Reliable Star-topology CSMA-CD Twisted Pair Cheap Bridging increases scalability Separate collision domains Full duplex operation (a) Single collision domain (b) High-Speed backplane or interconnection fabric
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60. Gigabit Ethernet Gigabit Ethernet Physical Layer Specification (IEEE 802.3 1 Gigabit Ethernet medium alternatives) Star Star Star Star Topology 100 m 25 m 5 km 550 m Max. Segment Length Twisted pair category 5 UTP Shielded copper cable Optical fiber single mode Two strands Optical fiber multimode Two strands Medium 1000baseT 1000baseCX 1000baseLX 1000baseSX
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65. Typical Ethernet Deployment Server 100 Mbps links 10 Mbps links Server Server Server 100 Mbps links 10 Mbps links Server 100 Mbps links 10 Mbps links Server Gigabit Ethernet links Gigabit Ethernet links Server farm Department A Department B Department C Hub Hub Hub Ethernet switch Ethernet switch Ethernet switch Switch/router Switch/router
71. Token Release T oken Frame T oken Frame Release after Transmission Release after Reception
72. Tokens and Data Frames Body Checksum Src addr Variable 48 Dest addr 48 32 End delimiter 8 Frame status 8 Frame control 8 Access control 8 Start delimiter 8