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connectivity from the server block to the core layer. Provides interswitch connectivity. Not typically used at this layer. Comparing Ether Media Requirements 10BaseT Duplex media interface connector (MIC) ST Differentiating between Connections AUI connectors are DB15 ISO 8877 (RJ45) connectors and jacks are slightly larger than RJ11 phone connectors and jacks Fiber Connector Port UTP Device The RJ45 Connector 1 8 8 Pair 4 R4 1 2 3 4 5 6 7 Wire Pair T is Tip R is Ring Pair 3 T2 Pair 3 R2 Pair 2 T3 Pair 1 R1 Pair 1 T1 Pair 2 R3 Pair 4 T4 Pin UTP Implementation Straightthrough Wires on cable ends are in same order Pin Label 1 RD+ 2 RD 3 TD+ 4 NC 5 NC 6 TD 7 NC 8 NC Cable 10BaseT/ 100BaseTx Straightthrough Pin Label 1 TD+ 2 TD 3 RD+ 4 NC 5 NC 6 RD 7 NC 8 NC Server/Router 8 1 w g g b w o w b o br w br 1 8 Straightthrough Cable 8 1 Hub/Switch 8 1 w g g b w o w b o br w br UTP Implementation Crossover Some wires on cable ends are crossed 8 1 w o o b w g w b g br w br Cable 10BaseT/ 100BaseT Crossover Pin Label 1 RD+ 2 RD 3 TD+ 4 NC 5 NC 6 TD 7 NC 8 NC Pin Label 1 RD+ 2 RD 3 TD+ 4 NC 5 NC 6 TD 7 N