Ethernet over Fiber, also known as IEEE 802.3z, is a standard that specifies the physical and data link layers of Ethernet networks using fiber-optic cabling. This standard defines Gigabit Ethernet over fiber optics, providing a data rate of 1 gigabit per second (Gbps). Here are the key aspects of Ethernet over Fiber (IEEE 802.3z):

  1. Data Rate: The standard provides a data rate of 1 Gbps, similar to Ethernet over Twisted Pair. However, Ethernet over Fiber achieves this data rate using fiber-optic cabling.
  2. Fiber-Optic Cabling: Ethernet over Fiber operates over fiber-optic cables, which are capable of transmitting data using light signals. Fiber-optic cables offer higher bandwidth, longer distances, and immunity to electromagnetic interference.
  3. Physical Layer: The standard defines the physical layer properties for Ethernet over Fiber, including different types of fiber-optic cables, connectors, signaling, and transmission characteristics.
  4. Multi-Mode and Single-Mode: Ethernet over Fiber supports both multi-mode and single-mode fiber-optic cables. Multi-mode cables are used for shorter distances, while single-mode cables are used for longer distances.
  5. Auto-Negotiation: Similar to other Ethernet standards, Ethernet over Fiber supports auto-negotiation to determine the highest common speed and duplex mode between connected devices.
  6. Full Duplex: The standard supports full-duplex operation, allowing simultaneous transmission and reception of data.
  7. Backward Compatibility: Ethernet over Fiber is backward compatible with lower-speed Ethernet standards, enabling different devices to communicate on the same network.
  8. Maximum Cable Length: The maximum cable length for Ethernet over Fiber depends on the type of fiber-optic cable used. Single-mode fiber can transmit data over longer distances compared to multi-mode fiber.
  9. Applications: Ethernet over Fiber is commonly used in scenarios where longer distances, higher bandwidth, and data security are required. It is used in data centers, campus networks, metropolitan area networks (MANs), and other applications.
  10. IEEE 802.3z: This is the official IEEE standard that defines Ethernet over Fiber. It ensures interoperability between devices from different manufacturers.

Ethernet over Fiber provides the advantages of fiber-optic technology, such as high-speed data transmission, immunity to electromagnetic interference, and the ability to cover longer distances. It is often chosen when the networking requirements exceed the capabilities of Ethernet over Twisted Pair, especially in environments where data security and reliability are critical.