Fiber

• Fiber-optic cable (fiber) is used to provide extremely fast connectivity for long distances.
• Typical speeds of 10, 40 and, 100 Gbps are transmitted on fiber, but higher speeds can be achieved.
• Distances will vary with the speed and type of cable being used; the typical range can be 150 meters to 120 kilometers (75 miles).
• Fiber comes in two variations from the service provider: lit fiber and dark fiber.
• Lit fiber (managed fiber) is similar to Verizon's FiOS service.

  • The provider is responsible for installing the fiber cable and for the equipment and maintenance on each end.
• Dark fiber is just a piece of fiber from one location to another, and the customer is responsible for lighting it and maintaining it.

  • Dark fiber is used inside the network campus, and it can also be used for WAN connectivity.
  • Dark fiber is the cheaper option after the upfront cost for equipment.
• Fiber is used to deliver several of the services covered in this chapter.