1. Gigabit Ethernet Nirmala Shenoy

2. Gigabit Ethernet • 1995 – interest in Gigabit Ethernet • Study group within 802.3 • Reasons • 100BaseT – vendors flooded market • Price fell • Popular as 10BaseT • Requirement for a faster interconnect

3. Gigabit Ethernet • Fast Ethernet to the desktop • Existing interconnects • FDDI at 100Mbps • ATM • Frame conversion • Backbones were aggregation points – bottlenecks

4. 100Base -> 1000Base • MII -> GMII ( gigabit Media Independent Interface • 4 to 8 bits parallel transfer from MAC to PHY • Each tx, rx lines operate at 125 MHz • To adopt an existing signaling scheme • 8B/10B coding of fibre channel adopted

5. Changes • Auto negotiation for fiber • Modification of CSMA/CD • Preference to full duplex

6. Modified slot-times • Slot time from 512 bits to 512 bytes • Min frame size – 512 bits • Carrier extension • Packet – packing