Cisco Certified Network Associate (CCNA) Practice Exam

What is the maximum length of the 1000BASE-SX cabling for 50-micron fiber?

1. 220 meters

2. 400 meters

3. 550 meters

4. 1 km

The correct answer is: 550 meters

The maximum length for 1000BASE-SX using 50-micron multimode fiber is indeed 550 meters. This standard is designed for short-distance applications in local area networks and utilizes multimode fiber to achieve high-speed data transmission. The choice of 50-micron fiber is prevalent in environments where distances are moderate, allowing for effective signal integrity and bandwidth, typically up to the specified 550 meters. This length and medium are suitable for environment setups like data centers or interconnected building networks, where quality fiber installations are crucial to maintaining high throughput. In contrast, options that suggest lengths shorter than 550 meters do not utilize the full capacity of the standard for 50-micron fiber. Similarly, those suggesting longer distances exceed the technical specifications outlined for 1000BASE-SX, which is defined to ensure optimal performance without degradation of the signal. Therefore, while several lengths might be relevant under specific conditions, 550 meters stands as the officially supported maximum for 1000BASE-SX over 50-micron fiber.