The decision to run single mode or multimode fiber depends on the specific needs and requirements of your network. Here are some factors to consider:

1.Distance: Single mode fiber is better suited for long distance transmission because it has a smaller core that allows light to travel straight down the fiber without bouncing off the edges. Multimode fiber is better for shorter distance transmission.

2. Bandwidth: Single mode fiber has a higher bandwidth capacity, making it suitable for high-speed, long-distance transmission. Multimode fiber has a lower bandwidth capacity and is better suited for shorter distance, lower-speed applications.

3. Cost: Single mode fiber tends to be more expensive than multimode fiber, so cost may be a factor in your decision.

4. Compatibility: Consider the compatibility of your existing equipment and the requirements of your network when choosing between single mode and multimode fiber.

Ultimately, the choice between single mode and multimode fiber will depend on your specific network requirements, budget, and compatibility considerations. It is recommended to consult with a network specialist or engineer to determine the best option for your needs.