ECOFRAME is a WDM optical packet ring that offers optical transparency and WDM statistical multiplexing and is a promising solution for the future metropolitan area networks. The optimal design of ECOFRAME ring requires the planning of the resources, i.e., wavelengths and receivers. However, the packet-nature of the ring requires a verification of the stability of the design, i.e., that the queueing delay experienced by the packets in the design is not unbounded. This paper proposes a joint approach for optimally designing the ECOFRAME ring, while ensuring system stability. The packet-aware design (PAD) approach is based on an integer linear programming formulation that accounts for the dynamic performance, by bounding the wavelength utilization. Results show the trade-off between ring cost and dynamic performance. The optimal PAD design incurs an incremental cost of about 30% in order to ensure the stability of the system.