3 different communication standards, each designed for specific purposes and applications: 1. **SONET (Synchronous Optical Network):** * **Purpose:** Originally designed to support the real-time, uncompressed transmission of voice circuits, SONET has since been extended to support data traffic. * **Key Features:** - Synchronous multiplexing: Different digital signals are synchronized to a clock, enabling their seamless aggregation. - Standardized rates: The basic level of SONET is OC-1 (Optical Carrier-1) which is 51.84 Mbps. It scales up with OC-3, OC-12, OC-48, and so on. - Built-in management and troubleshooting capabilities. - Redundancy through ring topology, ensuring high availability and fault tolerance. * **Use Case:** Used primarily by telecommunications companies to transport large amounts of telephone and data traffic. 2. **Gigabit Ethernet (GbE):** * **Purpose:** An extension of the Ethernet protocol, Gigabit Ethernet provides high-speed LAN and WAN connections. * **Key Features:** - Speeds of 1 Gbps, but the Ethernet family also includes standards like 10 GbE, 40 GbE, and 100 GbE, among others. - Compatible with existing Ethernet infrastructure, meaning upgrades can be more incremental. - Uses Carrier Sense Multiple Access with Collision Detection (CSMA/CD) for media access control. * **Use Case:** Used primarily for LANs, but also for some WAN connections, especially with the emergence of Metro Ethernet services. 3. **Fiber Channel (FC):** * **Purpose:** A high-speed data transfer protocol, primarily used for storage networking. * **Key Features:** - Speeds ranging from 1 Gbps to 128 Gbps. - Supports both point-to-point and switched topologies. - It's primarily a layer 2 protocol but has aspects that reach into layers 1 and 3. - Built for reliability with lossless data transport, making it essential for storage applications where data integrity is crucial. - Provides mechanisms for flow control and Quality of Service (QoS). * **Use Case:** Primarily found in Storage Area Networks (SANs) connecting servers to data storage devices. While all three standards can transmit data over optical fibers, they are optimized for different applications and environments. - SONET is rooted in the telecommunication industry, - Gigabit Ethernet is a popular standard for computer networks, - Fiber Channel is specially designed for storage connectivity.