A multicore optical fiber includes an inner glass region having a plurality of core regions surrounded by a common outer cladding, the inner glass region further having at least one marker and an outer diameter in the range of 120 microns and 130 microns, wherein each core region is comprised of a germania-doped silica core and a fluorine-doped silica trench, wherein the trench volume of the fluorine-doped silica trench is greater than 50% Δ microns2. The fiber has an outer coating layer surrounding the inner glass region, the outer coating layer having a primary coating layer and a secondary coating layer with a diameter of the secondary coating layer equal to or less than 200 microns, wherein each core region has a mode field diameter greater than 8.2 microns at 1310 nm, a cable cutoff wavelength of less than 1260 nm, and zero dispersion wavelength of less than 1335 nm.