Count the number of optical fiber boxes or ODF boxes, and multiply the number by the multiple of the optical fiber, such as 24-core optical fiber box (ODF), 24*2=48 cores, 24 cores at the start and 24 cores at the terminal;Count the number of optical fiber boxes or ODF boxes, and multiply the number by the multiple of the optical fiber, such as 24-core optical fiber box (ODF), 24*2=48 cores, 24 cores at the start and 24 cores at the terminal;The number of fiber cores is mainly related to the device interface of the fiber connection and the communication mode of the device. Generally speaking, the number of optical cores in an optical fiber is the total number of device interfaces multiplied by 2, plus 10% to 20% of the spare number. If. How to calculate number of fiber optic strand for backbone? for the following speed 10Gb/s & 40Gb/s Depends on distance you are looking to go. See link that shows top speeds per pair for fiber and Ethernet copper. For example, the total number of cores in an MTP®-8 trunk cable equals 4 (number of branches) x 8 (MTP-8. Fiber core count defines the maximum number of optical terminations or distribution points that a fiber enclosure can support.