This paper describes optical fiber and cable evaluation carried out at Bell-Northern Research during the summer period of May- August, 1980. Contemporary fibers and cables designed for telecommunications use were evaluated and the results on the following three areas are reported: (1) Resistance of fiber optics cables to temperature extremes and mechanical abuse. (2) Fiber tensile strength, both fast-fracture and fatigue, and a test method to predict longevity of the fibers. (3) Pulse broadening, measured as a function of link lengths in order to establish engineering rules which can predict performance for 10km lengths (typical repeater spacing) from the individual fiber characteristics. / Thesis / Master of Engineering (MEngr)