Subwavelength control of the electromagnetic field distribution represents one of the current challenges in photonics research. In this field, diffractive metasurfaces with spatially extended (i.e., nonlocal) resonant modes have recently gained great interest for their versatility in molding the electromagnetic field beyond the approximation of independent resonators. In this framework, we design a high-contrast nonlocal metasurface featuring modes situated in the third operating spectral window of optical communications. The optical properties of the fabricated metasurface are investigated by linear spectroscopy and numerical simulations. Our analysis allows to discern the magnetic and electric nature of the bounded modes by means of polarization-resolved reflectance measurements. Our results represent a step toward integrated nano-photonics in the telecom regime and open promising opportunities for the development of compact nonlinear optical devices.