The introduction of all-optical switching in data center interconnection networks (DCN) is key to addressing some of the shortcomings of state-of-the-art electronic switched solutions. Limitations in the port count, reconfiguration speed and cost of optical switches, however, require novel optical switching and DCN designs. We present the concept of a simplified DCN fabric that relies on a lean optical switch design of limited but scalable functionality that offers high reconfiguration speeds, real-time scheduling, efficient control and low equipment cost. To achieve these objectives, the proposed architecture relaxes the usual non-blocking switching requirements but opts for switching modules that are constrained in terms of the achievable space and wavelength input-output configurations. We analytically compare the functionality and complexity of the simplified fabric with those of a non-blocking switch. We evaluate the throughput performance of the simplified DCN fabric and compare it to that of other fabrics with a different level of functionality and centralized control.