The advent of nodal elements, such as Optical Add/Drop Multiplexers (OADM) for Wavelength Division Multiplexed (WDM) networks, has led to a myriad of possible network architectures for the optical layer. In this project we design and simulate a WDM-OADM optical ring system of four nodes, two wavelengths on unidirectional single mode fiber at data rates of up to 10 Gbps. We use a continuous wave laser as a source for each channel with external modulation. The performance of the system is reported on the basis of eye diagram, Bit Error Rate (BER) and Q-factor. Optisystem software is used to simulate the overall designed system.