Optimize the cost, due the transit is more expensive
Allowing you to dictate the route your traffic takes
Reduce the latency
Scalability
Cross Connect: Connectivity between customer’s rack to customer’s rack inside machine room or to external. Those connections are duct fiber, NNI capacity, and patching inside machine room or patching from machine room to external (ODF Outdoor).

Optimize the cost, due the transit is more expensive
Allowing you to dictate the route your traffic takes
Reduce the latency
Scalability
Follow customer demand: Bandwidth (1 Mbps to 10 Gbps), Interface (FE, GE, 10GE, …)