Shared and Switched Ethernet

🌐 Shared Ethernet

In Shared Ethernet, all devices are connected to a single broadcast medium. This architecture typically uses Hubs, which transmit signals to all connected devices.

• Channel Sharing: Multiple devices share the same physical medium. If two devices attempt to transmit at the same time, collisions occur, causing network inefficiencies.
• Collision Domain: All devices within the hub are in the same collision domain, meaning they share the same bandwidth.

Performance Considerations:

• Bandwidth Efficiency: Low due to collision overhead.
• Scalability Issues: As more devices are added, collision rates increase, further reducing throughput.

Key Protocol: CSMA/CD

• Devices use Carrier Sense Multiple Access with Collision Detection (CSMA/CD) to avoid collisions. If a collision is detected, all devices involved retransmit their data after a random backoff period.

⚡ Switched Ethernet

Switched Ethernet uses Ethernet switches instead of hubs, allowing devices to communicate without the risk of collisions.

• Point-to-Point Communication: Each device is connected to a dedicated switch port, and traffic is only directed to the specific destination device.
• Collision Domain: Each switch port is a separate collision domain, meaning no collisions occur unless there is congestion in the network.

Performance Considerations:

• Higher Efficiency: No collision overhead, allowing for higher throughput.
• Better Scalability: With the use of switches, more devices can be added without negatively impacting network performance.

Key Advantage: Dedicated Bandwidth

• Unlike Shared Ethernet, each device gets dedicated bandwidth, leading to more predictable performance and minimal interference.

📈 Comparison: Shared vs Switched Ethernet

🧠 Deep Insight

Switched Ethernet provides significant improvements in performance and scalability over Shared Ethernet. With the advent of switching technology, the reliance on collision avoidance mechanisms like CSMA/CD has diminished, leading to more efficient use of network resources.

“Ethernet switching has shifted the focus from merely avoiding collisions to ensuring dedicated communication channels, where each device can operate at its full potential.”

🧭 Key Takeaways

• Shared Ethernet is limited by collisions and bandwidth sharing, making it less efficient as the network grows.
• Switched Ethernet offers dedicated bandwidth to devices, eliminating collisions and providing better scalability and higher throughput.
• Switches significantly improve network performance by creating separate collision domains for each device.

🔗 Links

• Previous: Performance Analysis of MAC Protocols
• Next: IEEE Standards 802.3 & 802.11