Week 3: Ethernet Standard - M199205zn/Datacomm-CS3 GitHub Wiki

Ethernet Standards and Examples

Ethernet is a set of networking technologies and protocols used in local area networks (LANs), defined by the IEEE 802.3 standard. It specifies wiring and signaling standards for the physical layer and data link layer to enable communication between devices.

Ethernet Standards Categories

Ethernet standards are categorized based on speed, media type, and transmission mode:

1. Standard Ethernet (10 Mbps - IEEE 802.3)

  • Operates at 10 Mbps (Megabits per second).
  • Uses coaxial cable (10BASE5, 10BASE2) or twisted pair cable (10BASE-T).
  • Mostly obsolete but was widely used in early LANs.

🔹 Example:

  • 10BASE-T: Uses unshielded twisted pair (UTP) cables with RJ45 connectors.

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2. Fast Ethernet (100 Mbps - IEEE 802.3u)

  • Operates at 100 Mbps.
  • Requires Cat5 or better cables for transmission.
  • Uses CSMA/CD (Carrier Sense Multiple Access with Collision Detection) for media access.

🔹 Examples:

  • 100BASE-TX: Uses two pairs of twisted-pair cables (Cat5 or higher).
  • 100BASE-FX: Uses fiber-optic cables for long-distance communication.

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3. Gigabit Ethernet (1 Gbps - IEEE 802.3z, IEEE 802.3ab)

  • Operates at 1 Gbps (1000 Mbps).
  • Supports both twisted-pair and fiber-optic cables.
  • Introduced full-duplex communication to avoid collisions.

🔹 Examples:

  • 1000BASE-T: Uses all four pairs in a Cat5e/Cat6 UTP cable.
  • 1000BASE-SX: Uses multimode fiber for short-distance connections.
  • 1000BASE-LX: Uses single-mode fiber for longer distances.

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4. 10-Gigabit Ethernet (10 Gbps - IEEE 802.3ae, IEEE 802.3an)

  • Operates at 10 Gbps speed.
  • Used for high-speed data center networks and backbone connections.
  • Supports fiber and twisted-pair media.

🔹 Examples:

  • 10GBASE-T: Uses Cat6a or Cat7 UTP cables.
  • 10GBASE-SR: Uses multimode fiber for short distances.
  • 10GBASE-LR: Uses single-mode fiber for long distances.

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5. 40-Gigabit and 100-Gigabit Ethernet (IEEE 802.3ba, IEEE 802.3bj, IEEE 802.3bs)

  • Operates at 40 Gbps and 100 Gbps, mainly for data centers and cloud computing.
  • Uses advanced fiber-optic cabling.

🔹 Examples:

  • 40GBASE-SR4: Multimode fiber, short-range.
  • 100GBASE-LR4: Single-mode fiber, long-range.

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Conclusion

Ethernet has evolved from 10 Mbps to 100 Gbps, adapting to increased data demands. Different Ethernet standards serve various applications, from home networks (100BASE-TX) to high-performance data centers (100GBASE-LR4).